[INS-1789] Fix issue preventing selection of custom HTTP methods

[filfreire]

changelog(Fixes): Fixed an issue that prevented choosing and deleting user-created custom HTTP methods

Closes INS-1789
Closes #5083

This PR fixes two regressions:

• A user couldn't select an existing Custom HTTP method;
• A user couldn't delete more than one HTTP method at a time, needing to close and reopen the custom-methods dialogue.

These issues seem to have spawned from two problems:

• We returned early when trying to pick a custom method that already existed
• Relying on recent and setRecent doesn't seem to do what we think it does, and is only "valid for one change", hence why I edited the addition and deletion to rely on localStorage instead. I'm open to suggestions on how to improve this, it felt like a hacky workaround, but I couldn't find another way to make it work due to setRecent not working "a second time in a row" for the same time the modal is open.

⚠️ this PR doesn't solve a problem that we had before in earlier versions of Insomnia - where if we press Enter on the Custom Method modal, it is not seemingly picked up like pressing the Done button.

[jackkav]

🚀