Backport missing showRegisterLinks initializations to Palm

[yusuf-musleh]

Description

Backport of openedx#32783, includes missing initializations in JS files that were causing JS tests to fail.

(cherry picked from commit 3025ab5) (cherry picked from commit 2ee57b7d59ed53fa928f9b19127038b4cf0b4620)

Supporting information

Private-ref: BB-7694

Testing instructions

1. Set the SHOW_REGISTRATION_LINKS flag to False in both lms and cms
2. Check LMS: http://localhost:18000/ has no register button at the top
3. Check LMS: http://localhost:18000/register still works does work
4. Check LMS: http://localhost:18000/login doesn't show links to the registration form
5. Check CMS (studio): http://localhost:18010/ doesn't show links to register an account

[viadanna]

Approved based on openedx#32783