Add warnings when updating an extension with breaking changes

[arthuro555]

The warning messages are now clearer, translatable, and warns the user if the update type is unknown or breaking (major).

[arthuro555]

Ping

[D8H]

I tested manually. I don't see any issue.

• Update

• Major update

• Unknown

[D8H]

• What do you think about handling the case when a downgrade is done? It will happen when someone is working on an extension update or is trying one. Changing the button to "Downgrade" could help to avoid mistakes.

• Also, maybe the installed version could be shown next to the new version, with something like this:

            {extensionUpdate ?
            (<Trans>Version{' ' + extensionShortHeader.version + ' '} (installed:{' ' + extensionUpdate.currentVersion})</Trans>) :
            (<Trans>Version{' ' + extensionShortHeader.version}</Trans>)}

• Should the dialog be closed when the update is done?