fix IDE updater commands

[AlbyIanna]

Motivation

IDE updater commands are not working how expected. They work, but they are not giving any feedback to the user.

Change description

Remove useless commands. Leave only the "Check for Arduino IDE updates" command. When launching this command, if there is an update available, it opens the update dialog. If there isn't any update available or some error occurs, it shows a notification message.

Reviewer checklist

• PR addresses a single concern.
• The PR has no duplicates (please search among the Pull Requests before creating one)
• PR title and description are properly filled.
• Docs have been added / updated (for bug fixes / features)

[per1234]

@AlbyIanna if you still want me to check this out, please do a rebase to trigger a build. The build workflow is configured to only run on PRs submitted to the main branch, so it didn't run on the previous push. Now that the base has been changed to main it will run on the next update to the PR.

But I see Francesco already gave it the 👍, so it is good to merge right away.

[AlbyIanna]

@per1234 ✅ done!

[AlbyIanna]

@per1234 I've just realised I'm not updating the channel configuration immediately when the user changes the channel preference. It's not done until the next IDE start-up. I'm going to fix it in this PR because I think it's pertinent.

[AlbyIanna]

@per1234 Done. Now it should work as expected, that is when you change the channel or the update URL and then check for updates, the updater will use the correct channel/URL.

P.S.: I've noticed the expand/collapse icons in the bottom-right notifications are "invisible". Fixing it in another PR.

[per1234]

I had noticed the previous somewhat odd behavior of the commands, where you had to use a sequence of commands like this to trigger an update:

1. Arduino: Check for Arduino IDE updates
2. Arduino: Download Arduino IDE updates
3. Arduino: Install Arduino IDE updates

After which it would do the update regardless of whether the available version was newer than the current.

With this PR, the single command Arduino: Check for Arduino IDE updates does all that, and works the same as the automatic update offer. So I think it is a very nice improvement.

and also thought that the ones other than Arduino: Check for Arduino IDE updates didn't seem very useful. So I think this is a nice change.

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I verified that this also fixes #847

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Thanks Alberto!