Block library: Introduce block.json metadata for all client side blocks

[gziolo]

Description

This PR is a follow-up for #14551 which introduced a way to inline block.json metadata.

Scope covered by this PR:

• all static blocks (no PHP files) use block.json files for the following fields:
  • name
  • category
  • attributes

There were 2 exceptions where I couldn't easily move attributes to JSON file:

• in File block, where there is used translated default value for an attribute (https://github.com/WordPress/gutenberg/blob/master/packages/block-library/src/file/index.js#L64-L69)
• in Table block, where attributes are generated with JavaScript callback

I opened separate PRs for them: #14862 and #14863.

How has this been tested?

npm run test

npm run dev and ensure all blocks work as before.

[youknowriad]

I like this iterative approach. I left a few questions. I also saw that you didn't move the file block attributes because of the i18n issue, we should try the solution discussed in #core-js here.

[gziolo]

I like this iterative approach. I left a few questions. I also saw that you didn't move the file block attributes because of the i18n issue, we should try the solution discussed in #core-js here.

Yes, Tabel and File blocks have some challenges which I plan to resolve later this week.

Update: File block is being addressed in #14862. Table block is being addressed in #14863.

[youknowriad]

Let's iterate 👍