feat: remove key from built-in commands taken by custom commands

[noahfraiture]

PR Description

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)
• Docs have been updated if necessary
• You've read through your own file changes for silly mistakes etc

This PR aims to remove the key in keybindings for commands for which the key doesn't work because it is superseeded by a custom command.
Another possibility is to replace the key by the crossed version of the string.

[noahfraiture]

Hello, is there something I should do ? I don't have perm for labels I think

[stefanhaller]

Sorry for the delay.

While this is a bit of an improvement, I'm still hesitant to merge it because I have the feeling we should be able to do better. Ideally I'd like to make it so that all user-defined keybindings (whether for custom commands or builtin ones) always win over builtin bindings, even if one is local and the other is global. I don't have a very clear plan how to achieve that, but I have some vague ideas that I want to try at some point. For now, other topics have higher priority for me.