Offer types (and maybe vars/attributes) for completion

[FourierTransformer]

Since we are using tree-sitter we know what is being typed when a completion request comes in. There's a note in misc_handlers.tl to not try and provide type resolution, but it might be worth looking into while typing simple_type, var (which i think are local and global), and "attributes" (or what <const> and <total> are referred to as, I can't quite recall)

teal-language-server/src/teal_language_server/misc_handlers.tl

Lines 211 to 215 in 2dad2a7

	-- trying to define something new, probably don't want the in-scope thing to popup
	-- we could probably help complete simple types
	if node_info.parent_type == "var" or
	node_info.parent_type == "simple_type" or
	node_info.parent_type == "table_type" then