Autogenerate docs and autocompletion for composite block types

[rhazn]

This PR adds autogenerated documentation and autocompletion for composite block types.

Code autocompletion for composite block types

Because we have a lot of composite block types in domain extensions in the stdlib this PR also introduces an additional level in the documentation, blocks are now categorized as either "builtin" or by domain:

Inside each domain, the expected block definitions can be found:

Code autocompletion for composite block types

As a (happy?) accident of the refactoring, this PR also adds the existing composite block types to the autocompletion.

[rhazn]

Not sure I understand why the license compliance fails. The error seems to be

reuse._util - ERROR - Could not parse 'AGPL-3.0-only`;'
reuse.project - ERROR - 'apps/docs-generator/src/UserDocCategoryBuilder.ts' holds an SPDX expression that cannot be parsed, skipping the file

But I can spot no mistake in the license definition there? Does anyone else have a hunch?

[georg-schwarz]

Awesome 🥳 !

Does this also list the composite block types on root level of the stdlib, like the CSVExtractor?

[rhazn]

It does, they get listed as Built-in Blocktypes (imho correctly) :).