Fix whitespace issue in variable definition

[sadikovi]

Requirements

• Filling out the template is required. Any pull request that does not include enough information to be reviewed in a timely manner may be closed at the maintainers' discretion.
• All new code requires tests to ensure against regressions

Description of the Change

This PR fixes an issue when inserting a whitespaces after storage type in variable definition would break highlighting.

For example,

class A {
  String [] var1;
  int [] var2;
  List <String> var3;
}

Variables var1, var2, and var3 would not be scoped properly. I patched variables scope by inserting \s* to handle whitespaces for generics and arrays.

Alternate Designs

Adding a whitespace inside the matching pattern, but it seemed a bit odd to have it, plus, there was already a precedent to use it outside of matching groups.

Benefits

Fixes the highlighting.

Possible Drawbacks

None.

Applicable Issues

#196