Update DB format on install/upgrade if required

[phillxnet]

Older installs resulting from Rockstor-Leap15.3-generic.x86_64-4.1.0-0.install.iso Jan 14 2022 or earlier, that have also been zypper duped to at least a 15.4 base OS will now require a DB update prior to being compatible with the Django LTS 4.2 & psycopg3 that are used in current testing (5.0.6-0) and proposed next stable of 5.1.0-0.

Partner issue to rockstor-core:
"Establish Postgres database format upgrade": rockstor/rockstor-core#2780

• Establish new dependency to make pg_upgrade for target Postgres (13) available.
• Run via install/update scriptlets the shell script to be made available via the linked partner issue in rockstor-core.

[phillxnet]

pg_upgrade

zypper in --no-recommends postgresql13-contrib
Loading repository data...
Reading installed packages...
Resolving package dependencies...

The following 2 NEW packages are going to be installed:
  postgresql13-contrib postgresql-contrib

2 new packages to install.
Overall download size: 785.2 KiB. Already cached: 0 B. After the operation, additional 3.1 MiB will be used.
Continue? [y/n/v/...? shows all options] (y):

This looks to also have an alternatives setting:

installer:~ # which pg_upgrade 
/usr/bin/pg_upgrade
installer:~ # ls -la /usr/bin/pg_upgrade
lrwxrwxrwx 1 root root 28 Nov 10 12:38 /usr/bin/pg_upgrade -> /etc/alternatives/pg_upgrade
installer:~ # ls -la /etc/alternatives/pg_upgrade
lrwxrwxrwx 1 root root 36 Jan 20 18:55 /etc/alternatives/pg_upgrade -> /usr/lib/postgresql13/bin/pg_upgrade

pg_upgrade alternative setting

installer:~ # alternatives --display postgresql | grep pg_upgrade 
  slave pg_upgrade is /usr/bin/pg_upgrade
  slave pg_upgrade: /usr/lib/postgresql13/bin/pg_upgrade

Confirming that our existing Postgres alternatives ensures our default pg_upgrade is in line with out target Posgtres binary version.
I.e. from:
we have:

"Always run the pg_upgrade binary of the new server, not the old one."

This is assumed to be resolved via our Postgres alternatives setting, already in play.

[phillxnet]

Our linked partner-issue now has an associated draft PR:
"Establish Postgres database format upgrade ...": rockstor/rockstor-core#2781
proposing a DB format upgrade bash script.

We can now proceed to introduce the additional dependencies required by this script and test its invocation from the relevant scriptlets to enable auto DB format upgrade if required.

[phillxnet]

Closing as:
Fixed by #59