test: implement scale up and down tests and fix found issues

[Unix4ever]

Fixes:

• Check etcd health on all nodes before scaling down.
• Check all nodes are booted before scaling down.
• Do not call Shutdown during machine deletion (only for Talos >= 0.12.2).

Scale down tests are disabled for Talos < 0.12.2.

Signed-off-by: Artem Chernyshev artem.chernyshev@talos-systems.com

[Unix4ever]

/approve

[Unix4ever]

/m --ff