STACKITLB-798 | add ALB TF provider

[david-mey-STACKIT]

Description

STACKITLB-798

Add Application Load Balancer provider (API: https://docs.api.stackit.cloud/documentation/alb/version/v2)

Checklist

• Issue was linked above
• Code format was applied: make fmt
• Examples were added / adjusted (see examples/ directory)
• Docs are up-to-date: make generate-docs (will be checked by CI)
• Unit tests got implemented or updated
• Acceptance tests got implemented or updated (see e.g. here)
• Unit tests are passing: make test (will be checked by CI)
• No linter issues: make lint (will be checked by CI)

[h3adex]

imo we should use stackit_application_loadbalancer instead of stackit_alb as resource/datasource naming.

[marceljk]

remove this validator

[marceljk]

Please remove also the LengthBetween validator. We don't have for any resource a validation of the region and I prefer that we keep this consistent for alb

[marceljk]

wrong structure of the ID

Suggested change

	// loadbalancer terraform ID: = "[project_id],[name]"
	loadbalancerName := strings.Split(rs.Primary.ID, core.Separator)[1]
	loadbalancersToDestroy = append(loadbalancersToDestroy, loadbalancerName)
	// loadbalancer terraform ID: = "[project_id],[region],[name]"
	loadbalancerName := strings.Split(rs.Primary.ID, core.Separator)[2]
	loadbalancersToDestroy = append(loadbalancersToDestroy, loadbalancerName)

[marceljk]

Please check the failing CI pipeline