Implement major upgrade result annotations

[idanovinda]

In order to prevent Operator endlessly retrying on failing major version upgrade and also to be able to easily identify and be alerted on unsuccessful automated attempts, we need to implement a set of "Failed upgrade" annotations assigned to postgresql resource manifest.

Postgres-operator should annotate postgresql resource with one of the following values based on the return code of the upgrade script:

last-major-upgrade-success: <timestamp>
last-major-upgrade-failure: <timestamp>

Operator should:

• not execute the upgrade script if running PG version < manifest PG version but last-major-upgrade-failure is set
• remove the failure annotation if the running PG version >= manifest PG version
• set last-major-upgrade-failure when upgrade is failed
• set last-major-upgrade-success when upgrade is success

closes #2685