Pass a request object to custom page templates

[simonw]

Follow-up to #648. I'm not passing a request object to .render_template() at the moment, which breaks any other custom plugins using e.g. extra_template_vars() that were expecting to be able to access the request.

[simonw]

datasette/datasette/app.py

Lines 781 to 789 in 304e7b1

	body = await self.ds.render_template(
	template,
	{
	"custom_header": custom_header,
	"custom_status": custom_status,
	"custom_redirect": custom_redirect,
	},
	view_name="page",
	)

request is an optional argument here:

datasette/datasette/app.py

Lines 556 to 558 in 304e7b1

	async def render_template(
	self, templates, context=None, request=None, view_name=None
	):