fix(lsp): fix error with InsertReplaceEdit events #33973

Problem:
Some LSPs cause the following completion error (reformatted slightly):

    Error executing vim.schedule lua callback:
    .../runtime/lua/vim/lsp/completion.lua:373
    attempt to index field 'range' (a nil value)

This is because an internal function assumes edits are either missing
or of type `TextEdit`, but there's a third [possibility][0] that's not
handled: the `InsertReplaceEdit`.

This was previously reported in at least two issues:

- https://github.com/neovim/neovim/issues/33142
- https://github.com/neovim/neovim/issues/33224

Solution:
Don't assume the edit is a `TextEdit`. This implicitly handles
`InsertReplaceEdit`s.

Also, add a test case for this, which previously caused an error.

[0]: 2c07428966/runtime/lua/vim/lsp/_meta/protocol.lua (L1099)

(cherry picked from commit 927927e143)

runtime/lua/vim/lsp/completion.lua

@@ -370,7 +370,7 @@ end
 local function adjust_start_col(lnum, line, items, encoding)
   local min_start_char = nil
   for _, item in pairs(items) do
-    if item.textEdit and item.textEdit.range.start.line == lnum then
+    if item.textEdit and item.textEdit.range and item.textEdit.range.start.line == lnum then
       if min_start_char and min_start_char ~= item.textEdit.range.start.character then
         return nil
       end