Remove unnecessary setting change commands

[Gold856]

This removes all the commands for setting extension settings. I don't think people really use the settings commands, and the fact that VS Code has a GUI settings editor (which apparently it didn't when this extension was made because it's that old) makes these commands redundant. Note that this does not remove commands for setting the WPILib preferences JSON, because there's no GUI editor for that, although I doubt those commands get much usage...

[sciencewhiz]

I think this cleans up the menu, but the documentation will need to be updated, probably by making a new section for the extension preferences.

[Gold856]

I noticed there was a setting for selecting all simulation extensions by default, but it seems to not be implemented. This functionality technically exists already by just modifying build.gradle with .defaultEnabled = true added to any added extensions. Should we remove the setting in favor of modifying build.gradle, or should we implement the setting?

[sciencewhiz]

I noticed there was a setting for selecting all simulation extensions by default, but it seems to not be implemented. This functionality technically exists already by just modifying build.gradle with .defaultEnabled = true added to any added extensions. Should we remove the setting in favor of modifying build.gradle, or should we implement the setting?

I seem to recall it working in the past, but not necessarily being intuitive as to what it was doing.

[Gold856]

Given the lack of implementation, lack of reports of said implementation, and an alternative way to replicate its functionality, I'm just gonna remove it.