Logging and error handling improvements, bug fixes (#21)

- Uniformed logs and diagnostics:
  - Logging and adding to diagnostics is done by the highest level function (Create/Read/Update/Delete/Import) using `LogAndAddError`
  - Lower-level routines' signature changed to return error instead of writing to diagnostics
  - Standardize summary and details across services
  - Removed manual adding of relevant variables to details (they're in the context, TF adds them to logs)
- Changed validators to be closer to official implementation
- Fix logging wrong output after wait
- Fix Argus checking wrong diagnostics
- Fix Resource Manager not updating state after project update
- Fix unnecessary pointer in LogAndAddError

stackit/validate/validate_test.go

@@ -145,7 +145,7 @@ func TestNoSeparator(t *testing.T) {
 	}
 }
 
-func TestSemanticMinorVersion(t *testing.T) {
+func TestMinorVersionNumber(t *testing.T) {
 	tests := []struct {
 		description string
 		input       string
@@ -195,7 +195,7 @@ func TestSemanticMinorVersion(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.description, func(t *testing.T) {
 			r := validator.StringResponse{}
-			SemanticMinorVersion().ValidateString(context.Background(), validator.StringRequest{
+			MinorVersionNumber().ValidateString(context.Background(), validator.StringRequest{
 				ConfigValue: types.StringValue(tt.input),
 			}, &r)