* Pull request options migration and UI in settings
* Add ignore whitespace functionality
* Fix settings if pull requests are disabled
* Fix migration transaction
* Merge with Rebase functionality
* UI changes and related functionality for pull request merging button
* Implement squash functionality
* Fix rebase merging
* Fix pull request merge tests
* Add squash and rebase tests
* Fix API method to reuse default message functions
* Some refactoring and small fixes
* Remove more hardcoded values from tests
* Remove unneeded check from API method
* Fix variable name and comment typo
* Fix reset commit count after PR merge
