Relax the too restrictive begin expression for catch block

[Vigilans]

Description of the Change

Relax the too restrictive begin expression for catch block for following reasons:

• The begin pattern is not suitable for dealing with multi-line pattern.
• any comments between catch and ( would also break the highlighting.

Leave the catch keyword be would just be fine, since syntax highlighting should only be responsible for happy path.

Alternate Designs

Any other design would introduce new complexity.

Benefits

• Can correctly highlight when caught exceptions are split in multiple lines
• Can correctly highlight when '(' is placed in a new line after catch
• Can correctly highlight when there is comment between catch and '('
• Reduces the complexity

Possible Drawbacks

More like a right hightlight for wrong syntax in code.

Applicable Issues

Fix #205
FIx microsoft/vscode-java-pack#259

[sadikovi]

LGTM. Merging to master.