exp apply: force apply by default

[pmrowla]

• ❗ I have followed the Contributing to DVC checklist.

• 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.

Thank you for the contribution - we'll try to review it as soon as possible. 🙏

After discussion with @dmpetrov and @dberenbaum, overwriting any conflicting workspace changes with --force should be the default behavior when applying an experiment commit. Due to the nature of how we hide git usage behind experiments, it is not obvious to the user why applying an experiment can cause git conflicts, and in typical use cases for exp apply, overwriting conflicting changes is likely the behavior the user was already expecting to begin with.

• --no-force can be used to disable overwriting existing changes

[jorgeorpinel]

Hi. I don't think this was documented.

[pmrowla]

this PR is from before there were actual docs for experiments commands. It most likely got lost in the shuffle between when we stopped using the wiki for docs, and when my original exp command ref PR was opened and then closed (to be split up and managed separately on the docs repo side)

@jorgeorpinel

[jorgeorpinel]

Makes sense! I just happened to walk into this when updating all the exp cmd options (#2421).

Free to contribute something there (if you have a chance) and I'll polish it up. Thanks