Add admin password time indicator

[xf-]

Steps to reproduce

1. Use beta and update/enable/disable a plugin
2. Try to enter the required password
3. Modal closes after X seconds (with or without interaction)

Expected behaviour

Add a visual indicator like a progress-bar in CSS to maybe wait and reopen the window or close it on purpose (no possible, no X or ESC working).

Actual behaviour

While pasting from a password safe the modal closes do to a timeout (or if you start after few seconds it will close before you are done).

Nextcloud version: 14 beta 3

[nextcloud-bot]

GitMate.io thinks possibly related issues are #213 (Allow admin to define a password rules), #4634 (Add ability for admin to hide folders from users ), #4088 (after fresh install change of admin password and adding new user not possible), #3416 (admin password confirmation problem), and #1775 (Admin password stored in plain text).

[xf-]

annoying behavior stopped in v15