Migrate snippets follow up (#2789)

1. Skip snippets with fields we cannot migrate instead of just
discarding those fields
2. Show a untitled markdown document with the migration results
3. Use spoken forms/phrases from Talon

## Checklist

- [/] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [/] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [/] I have not broken the cheatsheet

---------

Co-authored-by: Phil Cohen <[email protected]>

Author: AndreasArvidsson

src/actions/generate_snippet.py

@@ -1,7 +1,7 @@
 import glob
 from pathlib import Path
 
-from talon import Context, Module, actions, settings
+from talon import Context, Module, actions, registry, settings
 
 from ..targets.target_types import CursorlessExplicitTarget
 
@@ -20,6 +20,15 @@ def private_cursorless_migrate_snippets():
         actions.user.private_cursorless_run_rpc_command_no_wait(
             "cursorless.migrateSnippets",
             str(get_directory_path()),
+            {
+                "insertion": registry.lists[
+                    "user.cursorless_insertion_snippet_no_phrase"
+                ][-1],
+                "insertionWithPhrase": registry.lists[
+                    "user.cursorless_insertion_snippet_single_phrase"
+                ][-1],
+                "wrapper": registry.lists["user.cursorless_wrapper_snippet"][-1],
+            },
         )
 
     def private_cursorless_generate_snippet_action(target: CursorlessExplicitTarget):  # pyright: ignore [reportGeneralTypeIssues]