Make the default branch link smaller in `branch-buttons` #2635

At some point we showed the default branch button as a small chevron by the branch selector (https://github.com/sindresorhus/refined-github/pull/1115) but we moved it away to group it with the “latest release” link. https://github.com/sindresorhus/refined-github/issues/1198

Since the space on that line is limited (https://github.com/sindresorhus/refined-github/issues/2624) (and I don’t need to know the name of the default branch in that particular view) I suggest moving the “default branch” link back to where it was, either as a chevron on the left or as an X on the right (of the branch selector)

The “latest release” button can stay as is.

This is what it used to look like

The feature could also be split since the two links wouldn’t be shown together anymore.