BCLV: Force scrollbar fixup if cleared.
Initial implementation of #9755.

- ImageFunctionsView now contains a text input allowing one to specify a
filter for its contained functions.
- When in filtered mode, the previous flattened view is used rather than
the hierarchical tree.
- The matching portion of the string is highlighted. However, currently
only simple string matches are supported.
Import RegExp classes from Ham.

Minor adjustments made by myself to fit into Haiku better.
Add ability to specify case insensitive matching.
Optimizations to filter match drawing.

Store the filter match index on the SourcePathComponentNode so we can
retrieve it directly when drawing instead of having to recompute the
position of the match every time.
Redo filtering to use new RegExp classes.

ImageFunctionsView's filtering field now allows shell-style glob matches
rather than just simple direct string matches. Implements remaining
part of #7955.