Block picker; retain english terms when translating keywords

[simison]

Is your feature request related to a problem? Please describe.

When keywords are translated, English search term gets lost:

keywords: [
	_x( 'columns', 'block search term', 'my-plugin' ),
	_x( 'images', 'block search term', 'my-plugin' ),
	_x( 'photos', 'block search term', 'my-plugin' ),
]

Now if my site is Spanish, I can only find this block using the search term "fotos". That's great, but if I'm maintaining multiple sites or otherwise just being bi-lingual, it would be useful to retain English search terms. I might've also seen a tutorial in one language while my site is in another, and I need to now guess how the English term got translated to my own language.

The same is true with the translated block name.

Describe the solution you'd like
I'd like both "fotos" and "photos" search terms return the block on Spanish site in the above example.

Describe alternatives you've considered

We can do this by duplicating the keywords, but that doesn't seem ideal:

keywords: [
	_x( 'columns', 'block search term', 'my-plugin' ),
	_x( 'images', 'block search term', 'my-plugin' ),
	_x( 'photos', 'block search term', 'my-plugin' ),
	'columns',
	'images',
	'photos',
]

Related to convo at #6633

[ocean90]

Also related: #11370