Search Plugin: Implement a simple Match Export Dialog

Implemented a very simple and bare-bones export dialog that allows generating a copy-able text containing only the regex-matched text regions. The dialog allows specifying a export pattern for the matched regular expression, making use of capture groups. The dialog is modeled after the awesome Export Matches function of https://regex101.com/

Let's say I want to get a List of classes from the Kate code-base, that are used with such a Pattern: ClassName::<whatever>. Then I would use the Search & Replace dialog to search for the pattern:

Right-Click on the results and choose Export matches. In the new Export Search Result Matches I would provide a generator pattern creating my export format. For example as csv:

Or just any other random pattern: