Migrate deprecated AllBranchesLogCmd to AllBranchesLogCmds

[ChrisMcD1]

• PR Description

Fixes #3961

Solves this by migrating allBranchesLogCmd into the preferred allBranchesLogCmds. This would be breaking behavior if somebody was relying on the behavior that is reported as a bug in #3961. If they did not specify a allBranchesLogCmd element, and added some additional allBranchesLogCmds elements, and wanted a full list. Such a behavior was never documented, and relying on a deprecated element seems like user error, so I'm not very worried about that. I would assume most people are like the one in the issue, where they assumed that they should put all of the items they want to cycle through in the allBranchesLogCmds, if they defined it.

• Please check if the PR fulfills these requirements

• Cheatsheets are up-to-date (run go generate ./...)
• Code has been formatted (see here)
• Tests have been added/updated (see here for the integration test guide)
• Text is internationalised (see here)
• If a new UserConfig entry was added, make sure it can be hot-reloaded (see here)
• Docs have been updated if necessary
• You've read through your own file changes for silly mistakes etc