Rename plugin to oik-blocks

[bobbingwide]

In its current state the oik-block plugin has two different roles

1. Prototype blocks for oik based shortcodes.
2. Logic to determine content compatibility with the block editor.

In the future, users will no longer need both. Once all content has been converted to blocks there will be no need for compatibility analysis.

So we should rename the plugin to reflect the fact that we’ll support multiple blocks.
And extract the content compatibility logic into a separate plugin - which could be called oik-block until we come up with a better name.

The reason for doing the rename first is to retain the Git change history.

[bobbingwide]

I've now cloned the plugin to https://github.com/bobbingwide/oik-blocks.
oik-block no longer needs any logic to create or register Gutenberg blocks.
A number of the issues should also be Transferred, using the 'Transfer this issue (Beta)' button.

The oik-block plugin will deliver:

• helper shortcodes: [blocks], [content], [guts]
• the logic that forms "opinions"
• the Preferred editor meta box
• batch utilities for checking site compatibility with Gutenberg

[bobbingwide]

The relevant issues have now been transferred. The oik-block code can now be updated to disable, then remove the JavaScript.

[bobbingwide]

oik-block's description, banner and icon should now be updated to reflect its changed role...
Gut feel - helps you form Gutenberg compatibility opinions