detect_fts should handle alternative table escaping

[simonw]

sqlite-utils now uses a better way of escaping table names, which has highlighted a bug in Datasette.

Datasette has its own version of the detect_fts function - at

datasette/datasette/utils/__init__.py

Lines 466 to 479 in d224ee2

	def detect_fts_sql(table):
	return r"""
	select name from sqlite_master
	where rootpage = 0
	and (
	sql like '%VIRTUAL TABLE%USING FTS%content="{table}"%'
	or (
	tbl_name = "{table}"
	and sql like '%VIRTUAL TABLE%USING FTS%'
	)
	)
	""".format(
	table=table
	)

- which fails to pick up FTS tables created using the new escaping pattern.

Originally posted by @simonw in simonw/sqlite-utils#57 (comment)