Feature/change user password

[informalict]

No description provided.

[maierlars]

Code looks good to me. (Two little suggestions)

Please add a in-cluster test. Those tests are in the /tests folder. The test should verify that changing the password secret indeed changes the password in the database.

[maierlars]

During testing the following occurred:

1. when the password secret is delete, the operator refuses to work. Instead nothing should happen.
2. after the bootstrap the root password is still empty and not as expected set the one in the secret. (current upstream master works fine)

[informalict]

During testing the following occurred:

1. when the password secret is delete, the operator refuses to work. Instead nothing should happen.
2. after the bootstrap the root password is still empty and not as expected set the one in the secret. (current upstream master works fine)

Ad 1) Fixed
Ad 2) Checked and found one issue where there was no error handling for generating random root password