feat: Better border configuration.

Started adding `resolve` which will allow you to do some really nice
stuff easily with options to get the window options from a variety of
inputs.

You can see how we do it in pickers.lua for borders & borderchars
currently.

lua/telescope/pickers/config_collapse.lua

@@ -1,103 +0,0 @@
-
---[[
-
-Ultimately boils down to getting `height` and `width` for:
-- prompt
-- preview
-- results
-
-No matter what you do, I will not make prompt have more than one line (atm)
-
-Result of `resolve` should be a table with:
-
-{
-  preview = {
-    get_width = function(self, max_columns, max_lines) end
-    get_height = function(self, max_columns, max_lines) end
-  },
-
-  result = {
-    get_width = function(self, max_columns, max_lines) end
-    get_height = function(self, max_columns, max_lines) end
-  },
-
-  prompt = {
-    get_width = function(self, max_columns, max_lines) return 1end
-    get_height = function(self, max_columns, max_lines) end
-  },
-}
-
-!!NOT IMPLEMENTED YET!!
-
-height =
-    1. pass between 0 & 1
-        This means total height as a percentage
-
-    2. pass a number > 1
-        This means total height as a fixed number
-
-    3. {
-        previewer = x,
-        results = x,
-        prompt = x,
-    }, this means I do my best guess I can for these, given your options
-
-    4. function(max_rows)
-        -> returns one of the above options
-        return max.min(110, max_rows * .5)
-
-        if columns > 120 then
-            return 110
-        else
-            return 0.6
-        end
-
-width =
-    exactly the same, but switch to width
-
-
-{
-    height = 0.5,
-    width = {
-        previewer = 0.25,
-        results = 30,
-    }
-}
-
-https://github.com/nvim-lua/telescope.nvim/pull/43
-
-After we get layout, we should try and make top-down sorting work.
-That's the next step to scrolling.
-
-{
-    vertical = {
-    },
-    horizontal = {
-    },
-
-    height = ...
-    width = ...
-}
-
---]]
-
-local resolver = {}
-
-local percentage_resolver = function(selector, percentage)
-  assert(percentage <= 1)
-  assert(percentage >= 0)
-
-  return function(...)
-    return percentage * select(selector, ...)
-  end
-end
-
-resolver.resolve_percentage_height = function(percentage)
-  return percentage_resolver(3, percentage)
-end
-
-resolver.resolve_percentage_width = function(percentage)
-  return percentage_resolver(2, percentage)
-end
-
-return resolver