Git - add context menu action to resolve merge conflicts (#1011)

* Git - wire up the codelens and command for merge conflict resolution

* Refactor code so that we are not using a codelens

* Rename folder

* Cleanup a change that is not needed

* Reorder imports

* Some code cleanup

* Update src/extension/git/vscode/mergeConflictParser.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Fix compilation error

* Attempt to fix tests

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>