AWS subnet split fixes

[mpagot]

This PR does not change anything in qe-sap two typical use-cases:

• 1 HANA node for mr_test
• 2 HANA nodes for HanaSR

But is supposed to allow going beyond 2 hana nodes, and more in general reduce the code complexity, makes the code more similar to the Azure one, change variable validation from regexp to a dedicated CIDR validation function.

Verification

HanaSR

sle-15-SP6-Qesap-Aws-Byos-x86_64-BuildLATEST_AWS_SLE15_6_BYOS-qesap_aws_fencing_native_test

• http://openqaworker15.qa.suse.cz/tests/311576 🟢 from http://openqaworker15.qa.suse.cz/tests/311576/logfile?filename=deploy-terraform.plan.log.txt is like it was before.

 + resource "aws_subnet" "infra-subnet" {
      + cidr_block                                     = "10.0.0.0/24"

...

  # module.hana_node.aws_instance.hana[0] will be created
  + resource "aws_instance" "hana" {
      + private_ip                           = "10.0.1.10"

...

  # module.hana_node.aws_instance.hana[1] will be created
  + resource "aws_instance" "hana" {
      + private_ip                           = "10.0.2.11"

...

  # module.hana_node.aws_subnet.hana-subnet[0] will be created
  + resource "aws_subnet" "hana-subnet" {
      + cidr_block                                     = "10.0.1.0/24"
...

  # module.hana_node.aws_subnet.hana-subnet[1] will be created
  + resource "aws_subnet" "hana-subnet" {
      + cidr_block                                     = "10.0.2.0/24"

Job failure is later for timeout in crm resource refresh msl_SAPHanaCtl_HQ0_HDB00

• http://openqaworker15.qa.suse.cz/tests/311635 🟢

mr_test

sle-12-SP5-EC2-SAP-BYOS-Incidents-saptune-x86_64-Build:36967:kernel-ec2-sles4sap_gnome_saptune_delete_rename@ec2_r5b.metal -> http://openqaworker15.qa.suse.cz/tests/311636

[lpalovsky]

LGTM

[BillAnastasiadis]

LGTM