One exception: there is an existing MR for the current branch and the
branch is non-default and non-protected.

Extended mock_data for ide/stores to have different types of branches:
default, protected and regular

Cleaned new MR checkbox view

- Pull the new MR option out into it's own component
- Default MR checkbox to true when creating a new MR and committing to a
  branch that does not have an MR
- Still change the MR checkbox to false when a user is on a branch that
  already has an MR
- Hide MR option when on a branch that already has an MR and committing
  to current branch
- Don't default to true when committing directly to master

Closes #47843

created reset action to reset stored merge requests

Closes #45184

Closes #44604

Closes #45698

fixed ide_tree_spec.js