feat(alb) migrate to versioned sdk

[cgoetz-inovex]

STACKITTPR-533

Description

relates to #1234

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)

[github-actions]

Merging this branch will increase overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion	39.32% (+6.30%)	👍
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer	64.34% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/utils	75.00% (ø)

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion/conversion.go	39.32% (+6.30%)	117 (+11)	46 (+11)	71	👍
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer/datasource.go	0.00% (ø)	43	0	43
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer/resource.go	67.31% (ø)	933	628	305
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/utils/util.go	75.00% (ø)	8	6	2

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion/conversion_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/alb_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer/resource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/utils/util_test.go

[rubenhoenle]

Since this is basically a copy of StringSetToPointer, couldn't we adjust it to re-use this logic here? So we don't have duplicates?

// StringSetToPointer converts basetypes.SetValue to a pointer to a list of strings.
// It returns nil if the value is null or unknown.
// Note: It sorts the resulting slice to ensure deterministic behavior.
func StringSetToPointer(set basetypes.SetValue) (*[]string, error) {
   result := StringSetToSlice(set)
   return &result
}

[rubenhoenle]

Rest looks good.