Auto-resolve for the same

[porceCodes]

Due the the git's definition of a conflict, the identical content of an existing change and an incoming change may still be presented as a conflict that requires the human intervention.

• Request 1: How about adding "Auto-resolve" when GitLens detect they are indeed the same, hence it does not matter to take any of the existing change or incoming change.
• Request 2: Add a configuration parameter in settings, when a file with conflict markers open, GitLens performs auto-resolve the eligible conflicts AND save, so that git diff automatically can show what is auto-resolved
• Request 3: Support a custom rule of auto-resolve in a form of external shell script. Input to the shell script is two files: _existing_change_some_id.gitlens, and _incoming_change_some_id.gitlens, and the return value from the shell script is either 0 (for success) or 1 (for error). The user may optionally specify the path to the user-providing shell script.