Add support for PXC operator v1.16.1

I tested MySQL and MongoDB upgrades and ran regression tests on both; they work fine: CLI works fine without issues.

I have not run a test with HELM since this is not ready yet, but after talking with ​@Oksana Grishchenko, we agreed to test CLI since this includes the installations with Helm.

[Video] This is the Upgrade of both Operators:

And testing of regression:

• Creation of Databases with different nodes quantity

• Monitoring PMM

• Backups/Restores

• Restoring from a Database

• Modification of data

I created an improvement for the UI:

Running the Upgrade:

Talking with Oksana, I followed these steps https://www.notion.so/percona/Everest-Feature-Builds-FBs-153674d091f38054baf9c4160b8e62dc#168674d091f380029f46ce5231fd0f68

Installed Percona Everest 1.4.0 as usual

Installed the FB service and forwarded it as well

Run the upgrade

UPD:

FB that contains and together:

Scope to be tested:

Regression Test of the Operators:

• Verify if everything in the operator is functioning correctly, including upgrades.

• Ensure there is no database restart.

• This should be automated in the future (no manual testing for this type of ticket).

Feature build: (only PXC included for now)