Fix repeat-mode to keep the same map symbol for repeat-continue

Fix repeat-mode to keep the same map symbol for repeat-continue

* lisp/repeat.el (repeat-get-map-sym): New function
refactored from 'repeat-get-map'.
(repeat-get-map): Move continue-related code to 'repeat-get-map-sym'.
(repeat-pre-hook): Use 'repeat-get-map-sym' and 'repeat-get-map'.
Set 'repeat-map' to 'map-sym'.
(repeat-post-hook): Use 'repeat-get-map-sym'.

* test/lisp/repeat-tests.el (repeat-tests-continue-another):
Improve to invoke double key 'C-M-o C-M-o' that should not switch
between maps (bug#74140).

(cherry picked from commit 0bd12f560b0b288e6c7717bf2e0f664c17d07619)