backport test: lint naming conventions (#39124)

test: lint naming conventions

Problem:
Naming conventions are not automatically checked.

Solution:
Add a check to the doc generator. Eventually we should extract this
somehow, but that will require refactoring the doc generator...

Note: this also checks non-public functions, basically anything that
passes through `gen_eval_files.lua` and `gen_vimdoc.lua`. And that's
a good thing.

runtime/lua/vim/lsp/client.lua

@@ -1071,17 +1071,17 @@ end
 --- Execute a lsp command, either via client command function (if available)
 --- or via workspace/executeCommand (if supported by the server)
 ---
---- @param command lsp.Command
+--- @param cmd lsp.Command
 --- @param context? {bufnr?: integer}
 --- @param handler? lsp.Handler only called if a server command
-function Client:exec_cmd(command, context, handler)
+function Client:exec_cmd(cmd, context, handler)
   context = vim.deepcopy(context or {}, true) --[[@as lsp.HandlerContext]]
   context.bufnr = vim._resolve_bufnr(context.bufnr)
   context.client_id = self.id
-  local cmdname = command.command
+  local cmdname = cmd.command
   local fn = self.commands[cmdname] or lsp.commands[cmdname]
   if fn then
-    fn(command, context)
+    fn(cmd, context)
     return
   end
 
@@ -1099,12 +1099,12 @@ function Client:exec_cmd(command, context, handler)
     )
     return
   end
-  -- Not using command directly to exclude extra properties,
+  -- Not using cmd directly to exclude extra properties,
   -- see https://github.com/python-lsp/python-lsp-server/issues/146
   --- @type lsp.ExecuteCommandParams
   local params = {
     command = cmdname,
-    arguments = command.arguments,
+    arguments = cmd.arguments,
   }
   self:request('workspace/executeCommand', params, handler, context.bufnr)
 end