Address Xlint:unchecked?

[ice1000]

arend>gradlew classes

> Task :base:compileJava
arend\base\src\main\java\org\arend\extImpl\userData\UserDataHolderImpl.java:18: warning: [uncheck
ed] unchecked cast
    return myUserDataMap == null ? null : (T) myUserDataMap.get(key);
                                                               ^
  required: T
  found:    Object
  where T is a type-variable:
    T extends Object declared in method <T>getUserData(@org.jetbrains.annotations.NotNull Key<T>)
arend\base\src\main\java\org\arend\typechecking\visitor\CheckTypeVisitor.java:401: warning: [unch
ecked] unchecked cast
      return result == null ? null : (List<CorePattern>) (List<?>) result.getPatterns();
                                                         ^
  required: List<CorePattern>
  found:    List<CAP#1>
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?
arend\base\src\main\java\org\arend\core\pattern\ConstructorExpressionPattern.java:58: warning: [u
nchecked] unchecked cast
    return (List<? extends ExpressionPattern>) super.getSubPatterns();
                                                                   ^
  required: List<? extends ExpressionPattern>
  found:    @org.jetbrains.annotations.NotNull List<CAP#1>
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Pattern from capture of ? extends Pattern
arend\base\src\main\java\org\arend\core\pattern\ConstructorExpressionPattern.java:87: warning: [u
nchecked] unchecked cast
      link = pattern.replaceBindings(link, (List<Pattern>) (List<?>) subPatterns);
                                                           ^
  required: List<Pattern>
  found:    List<CAP#1>
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?
arend\base\src\main\java\org\arend\typechecking\implicitargs\equations\LevelEquationsSolver.java:
41: warning: [unchecked] unchecked cast
        addEquation((LevelEquation<InferenceLevelVariable>) (LevelEquation<?>) levelEquation, false);
                                                            ^
  required: LevelEquation<InferenceLevelVariable>
  found:    LevelEquation<CAP#1>
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?
arend\base\src\main\java\org\arend\module\serialization\DefinitionDeserialization.java:78: warnin
g: [unchecked] unchecked cast
        SerializableKey<Object> key = (SerializableKey<Object>) myKeyRegistry.getKey(entry.getKey());
                                                                                    ^
  required: SerializableKey<Object>
  found:    SerializableKey<CAP#1>
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?
arend\base\src\main\java\org\arend\module\serialization\DefinitionSerialization.java:74: warning:
 [unchecked] unchecked cast
        SerializableKey<Object> key = (SerializableKey<Object>) entry.getKey();
                                                                            ^
  required: SerializableKey<Object>
  found:    Key<CAP#1>
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?
arend\base\src\main\java\org\arend\typechecking\visitor\DesugarVisitor.java:261: warning: [unchec
ked] unchecked cast
        visitClassFieldImpl((Concrete.ClassFieldImpl) element, (List<Concrete.ClassFieldImpl>) elements);
                                                                                               ^
  required: List<ClassFieldImpl>
  found:    List<T>
  where T is a type-variable:
    T extends ClassElement declared in method <T>visitClassElements(List<T>,Void)
arend\base\src\main\java\org\arend\typechecking\visitor\FindDefCallVisitor.java:76: warning: [unc
hecked] unchecked cast
      myFoundDefinitions.add((T) expression.getDefinition());
                                                         ^
  required: T
  found:    @org.jetbrains.annotations.NotNull Definition
  where T is a type-variable:
    T extends Definition declared in class FindDefCallVisitor
9 warnings

> Task :cli:compileJava
arend\cli\src\main\java\org\arend\frontend\parser\BuildVisitor.java:550: warning: [unchecked] unc
hecked cast
    return returnExprCtx == null ? new Pair<>(null, null) : (Pair<Concrete.Expression,Concrete.Expression>) visit(returnExprCtx)
;
                                                                                                                 ^
  required: Pair<Expression,Expression>
  found:    Object
arend\cli\src\main\java\org\arend\frontend\parser\BuildVisitor.java:555: warning: [unchecked] unc
hecked cast
    return returnExprCtx == null ? new Pair<>(null, null) : (Pair<Concrete.Expression,Concrete.Expression>) visit(returnExprCtx)
;
                                                                                                                 ^
  required: Pair<Expression,Expression>
  found:    Object
arend\cli\src\main\java\org\arend\frontend\ui\CliSession.java:30: warning: [unchecked] unchecked
cast
      this.query = (SimpleQuery<Object>) query;
                                         ^
  required: SimpleQuery<Object>
  found:    SimpleQuery<CAP#1>
  where CAP#1 is a fresh type-variable:
    CAP#1 extends Object from capture of ?
3 warnings

[ice1000]

Some are impossible to address in my opinion