Request to add the option to type a forward slash / to call up a list of blocks and insert one

[designsimply]

On the web, if you type a forward slash into an empty block it will call up a list of blocks and you can insert a block by typing out it's name or selecting one. Would it be possible to add that option to Gutenberg Mobile?

Chrome on Android	WPAndroid 15.7 beta

^{Tested with WPAndroid 15.7-rc-3 on Pixel 3 Android 11.}

^{(Originally reported in beta testing, internal reference: p5T066-1vr-p2#comment-5840)}

[chipsnyder]

We ended up taking this on as a HackWeek project and will be wrapping it up as we have time between projects. The current status is being tracked in this PR WordPress/gutenberg#29772