feat: asyncify pickers - except for live_grep (#709)

* something kind of works already

* yayayayayayayayayayayayayayayayayayayayayayayayayayayayayayayayaya

* use async for everything besides live jobs

* fix: fixup autocmds previewer

* fix: lints for prime

* temp: Add example of how we can think about async sorters

* feat: Allow picker to decide when to cancel

* fix: simplify scoring logic and tests

* fixup: name

* fix: Move back towards more backwards compat methods

* fixup: Remove results from opts

* fixup: remove trailing quote

* fixup: Attempt to clean up some more async items. Next is status

* wip: Add todo for when bfredl implements extmarks over the EOL

* wip

* fixup: got em

* fixup: cleaning

* fixup: docs

lua/telescope/pickers/window.lua

@@ -0,0 +1,17 @@
+local p_layouts = require('telescope.pickers.layout_strategies')
+
+local p_window = {}
+
+function p_window.get_window_options(picker, max_columns, max_lines)
+  local layout_strategy = picker.layout_strategy
+  local getter = p_layouts[layout_strategy]
+
+  if not getter then
+    error("Not a valid layout strategy: " .. layout_strategy)
+  end
+
+  return getter(picker, max_columns, max_lines)
+end
+
+
+return p_window