extra_ plugin hooks should take the same arguments

[simonw]

• extra_css_urls(template, database, table, datasette)
• extra_js_urls(template, database, table, datasette)
• extra_body_script(template, database, table, view_name, datasette)
• extra_template_vars(template, database, table, view_name, request, datasette)

Originally posted by @simonw in #938 (comment)

[simonw]

They should all take:

template, database, table, view_name, request, datasette, columns

columns is new, see #938.

[simonw]

They should also be next to each other in the documentation - right now they're a bit scattered in terms of page order:

[simonw]

I'm going to implement this first as a single commit, then implement columns from #938 as a separate change.

[simonw]

Also: they should all be able to return async def inner functions. At the moment only extra_template_vars supports that pattern.

[simonw]

And the docs need to be updated too.

[simonw]

Docs also need to note that request may be None for all of these hooks.