feat: (IAC-1089) Valid PG Server Name and Update Doc

[jarpat]

Changes

• Added a validation for the names of the postgres servers, so we did not run into failures when the hostname is assigned.
  • Acceptable format: Postgres Server names must follow a valid naming scheme. Name must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character
• Automatically convert any postgres server names that have a hyphen inside them (e.g. cds-postgres) to be an underscore inside the group headings within the inventory file. The postgres_server_name variable inside the inventory file will still have hyphens.
• Updated doc to reflect these changes, and also synced up Postgres doc with other cloud repos.

Tests

Scenario	Provider	K8s	Postgres Servers	Action	Order	Cadence	Notes
1	vSphere	1.26.7	default & cds-postgres	apply, setup, install	**	fast:2020	deployment successful, both servers used by Viya deployment
2	vSphere	1.26.7	default	apply, setup, install	n/a	n/a	default user scenario still works
3	vSphere	1.26.7	null	apply, setup, install	n/a	n/a	no pg server created, validation error was not thrown
4	vSphere	1.26.7	-servername123	plan	n/a	n/a	variable validation error thrown
5	vSphere	1.26.7	servername123-	plan	n/a	n/a	variable validation error thrown
6	vSphere	1.26.7	server_name123	plan	n/a	n/a	variable validation error thrown
7	vSphere	1.26.7	server*name123	plan	n/a	n/a	variable validation error thrown
8	vSphere	1.26.7	server-name-123	plan	n/a	n/a	validation error was not thrown

[jarpat]

Adding the test results here since it properly handles larges table in comments.

Tests

Scenario	Provider	K8s	Postgres Servers	Action	Order	Cadence	Notes
1	vSphere	1.26.7	default & cds-postgres	apply, setup, install	**	fast:2020	deployment successful, both servers used by Viya deployment
2	vSphere	1.26.7	default	apply, setup, install	n/a	n/a	default user scenario still works
3	vSphere	1.26.7	null	apply, setup, install	n/a	n/a	no pg server created, validation error was not thrown
4	vSphere	1.26.7	-servername123	plan	n/a	n/a	variable validation error thrown
5	vSphere	1.26.7	servername123-	plan	n/a	n/a	variable validation error thrown
6	vSphere	1.26.7	server_name123	plan	n/a	n/a	variable validation error thrown
7	vSphere	1.26.7	server*name123	plan	n/a	n/a	variable validation error thrown
8	vSphere	1.26.7	server-name-123	plan	n/a	n/a	validation error was not thrown