Feat(exasol): support bracket-delimited identifiers (#6231)

Though maybe this changed recently, I can't find it anywhere in the documentation.

Author: JoepvandenHoven-Bluemine

sqlglot/dialects/exasol.py

@@ -115,6 +115,7 @@ class Exasol(Dialect):
     }
 
     class Tokenizer(tokens.Tokenizer):
+        IDENTIFIERS = ['"', ("[", "]")]
         KEYWORDS = {
             **tokens.Tokenizer.KEYWORDS,
             "USER": TokenType.CURRENT_USER,

tests/dialects/test_exasol.py

@@ -5,6 +5,12 @@ class TestExasol(Validator):
     dialect = "exasol"
     maxDiff = None
 
+    def test_exasol(self):
+        self.validate_identity(
+            "SELECT 1 AS [x]",
+            'SELECT 1 AS "x"',
+        )
+
     def test_type_mappings(self):
         self.validate_identity("CAST(x AS BLOB)", "CAST(x AS VARCHAR)")
         self.validate_identity("CAST(x AS LONGBLOB)", "CAST(x AS VARCHAR)")