Add a --merge command line option

[Malacath-92]

Add a --merge command line option, mirroring --diff. This is necessary to merge conflicts in version control systems other than git, such as perforce. Currently we are restricted to using only git as one criteria for showing the conflict resolution widgets seems to be that the opened file is in the MERGE section of the version control tab, which can't be guaranteed when using perforce.

The CLI I suggest would be --merge <merged_file> <their_file> <your_file> or simply --merge <merged_file>

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Git merge conflict not detecting (#114397)
• Whitespaces changes not ignored in Merge Conflict View (#128976)
• Git extensions UI isn't able to show a merge conflict with 1 file when there are 10k staged changes in the merge (VS can) (#129669)
• Source Control tab and Merge conflict detection (#125413)

[Malacath-92]

Presumably this is a duplicate of this issue I'm not sure how I missed that, but seeing said issue from 5 years ago does not instill confidence that we will see this feature anytime soon.