feat(picker): command history filter (#2132)

* feat(picker): command history filter

I've recently start using command history. For sometime was a bit annoyed of unrelevant commands
like edit/write and others (most likely only used once)

I've considered using lua patterns, however, logical `or` isn't a thing. Additionally, passing a list of lua patterns and checking each pattern for each command history entry felt tedious.

This PR introduce a new optional function to filter command history items.

For example, in my configurations

~~~lua
local command_history_ignore = vim.regex "edit\\|Move\\|write\\|Write\\|e\\s\\|lua\\sI("
overrides.command_history = minimal {
  prompt_prefix = "CMDHistory> ",
  filter_fn = function(item)
    if #item < 3 then
      return false
    else
      return not command_history_ignore:match_str(item)
    end
  end,
}
~~~

* [docgen] Update doc/telescope.txt
skip-checks: true

Co-authored-by: Github Actions <actions@github>

lua/telescope/builtin/__internal.lua

@@ -542,10 +542,20 @@ internal.command_history = function(opts)
   local history_list = vim.split(history_string, "\n")
 
   local results = {}
+  local filter_fn = opts.filter_fn
+
   for i = #history_list, 3, -1 do
     local item = history_list[i]
     local _, finish = string.find(item, "%d+ +")
-    table.insert(results, string.sub(item, finish + 1))
+    local cmd = string.sub(item, finish + 1)
+
+    if filter_fn then
+      if filter_fn(cmd) then
+        table.insert(results, cmd)
+      end
+    else
+      table.insert(results, cmd)
+    end
   end
 
   pickers