Block Field Suggestions Plugin Does Not Mask Enum Suggestions

[sselby]

When a parsing error occurs on an enum an error message with suggestions can be returned. This message will be of a form like:

• Variable "$category" got invalid value "FFICTION"; Value "FFICTION" does not exist in "Category" enum. Did you mean the enum value "FICTION"?

It can also return more than one suggestion:

• Variable "$category" got invalid value "FFICTION"; Value "FFICTION" does not exist in "Category" enum. Did you mean the enum value "FICTION" or "NON_FICTION"?

The extra "the enum value" and potential of multiple suggestions is not matched by the current regular expression.

[nullswan]

cc @QuentinN42 @Gby56