AB#2386: TrustedLaunch support for azure attestation

* There are now two attestation packages on azure.
The issuer on the server side is created base on successfully
querying the idkeydigest from the TPM. Fallback on err: Trusted Launch.
* The bootstrapper's issuer choice is validated by the CLI's validator,
which is created based on the local config.
* Add "azureCVM" field to new "internal-config" cm.
This field is populated by the bootstrapper.
* Group attestation OIDs by CSP (#42)
* Bootstrapper now uses IssuerWrapper type to pass
the issuer (and some context info) to the initserver.
* Introduce VMType package akin to cloudprovider. Used by
IssuerWrapper.
* Extend unittests.
* Remove CSP specific attestation integration tests

Co-authored-by: <dw@edgeless.systems>
Signed-off-by: Otto Bittner <cobittner@posteo.net>

internal/watcher/validator_test.go

@@ -91,12 +91,17 @@ func TestNewUpdateableValidator(t *testing.T) {
 					filepath.Join(constants.ServiceBasePath, constants.EnforceIdKeyDigestFilename),
 					[]byte("false"),
 				))
+				require.NoError(handler.Write(
+					filepath.Join(constants.ServiceBasePath, constants.AzureCVM),
+					[]byte("true"),
+				))
 			}
 
 			_, err := NewValidator(
 				logger.NewTest(t),
 				tc.provider,
 				handler,
+				false,
 			)
 			if tc.wantErr {
 				assert.Error(err)
@@ -147,6 +152,10 @@ func TestUpdate(t *testing.T) {
 		filepath.Join(constants.ServiceBasePath, constants.EnforceIdKeyDigestFilename),
 		[]byte("false"),
 	))
+	require.NoError(handler.Write(
+		filepath.Join(constants.ServiceBasePath, constants.AzureCVM),
+		[]byte("true"),
+	))
 
 	// call update once to initialize the server's validator
 	require.NoError(validator.Update())
@@ -213,6 +222,10 @@ func TestUpdateConcurrency(t *testing.T) {
 		filepath.Join(constants.ServiceBasePath, constants.EnforceIdKeyDigestFilename),
 		[]byte("false"),
 	))
+	require.NoError(handler.Write(
+		filepath.Join(constants.ServiceBasePath, constants.AzureCVM),
+		[]byte("true"),
+	))
 
 	var wg sync.WaitGroup