Improve Visual Basic comments filtering

[Vladyslav-Kuksiuk]

This PR improves comments filtering for Visual Basic.

Resolves this issue.

[Oleg-Melnik]

Optional cleanup (non-blocking): visualBasicQuotedSegmentEnd structurally mirrors the shared quotedSegmentEnd in marker_comment_filter.go, differing only in escape semantics ("" doubled-quote vs \ backslash). A dedicated function reads clearly here, so no change is needed now — but if a third quote-escaping style ever appears, it'd be worth generalizing the shared helper to take an escape strategy rather than adding another near-duplicate.

[Oleg-Melnik]

@Oleg-Melnik LGTM with a minor comment.

[Vladyslav-Kuksiuk]

Optional cleanup (non-blocking): visualBasicQuotedSegmentEnd structurally mirrors the shared quotedSegmentEnd in marker_comment_filter.go, differing only in escape semantics ("" doubled-quote vs \ backslash). A dedicated function reads clearly here, so no change is needed now — but if a third quote-escaping style ever appears, it'd be worth generalizing the shared helper to take an escape strategy rather than adding another near-duplicate.

Resolved in the following PR.