feat: make authMethod nullable

There are some circumstances where we cannot set authMethod, which requires us to pass null.

JIRA: LX-671
risk: low

Author: chrisbonilla95

gooddata-server-oauth2-autoconfigure/src/main/kotlin/AuthenticationProcessor.kt

@@ -46,7 +46,7 @@ sealed class AuthenticationProcessor<in authenticationToken : AbstractAuthentica
         organization: Organization,
         user: User,
         name: String?,
-        authMethod: AuthMethod,
+        authMethod: AuthMethod?,
         monoProvider: () -> Mono<T>,
     ): Mono<T> = monoProvider().contextWrite(
         reactorUserContextProvider.getContextView(organization.id, user.id, name, user.usedTokenId, authMethod)

gooddata-server-oauth2-autoconfigure/src/main/kotlin/UserContextHolder.kt

@@ -62,7 +62,7 @@ fun interface ReactorUserContextProvider {
         userId: String,
         userName: String?,
         tokenId: String?,
-        authMethod: AuthMethod
+        authMethod: AuthMethod?,
     ): ContextView
 }
 
@@ -89,7 +89,7 @@ interface AuthenticationUserContext {
     /**
      * Method of authentication
      */
-    val authMethod: AuthMethod
+    val authMethod: AuthMethod?
 }
 
 enum class AuthMethod(val value: String) {

gooddata-server-oauth2-autoconfigure/src/test/kotlin/UserContextWebFluxTest.kt

@@ -600,7 +600,7 @@ class UserContextWebFluxTest(
         override val userId: String,
         val userName: String?,
         override var tokenId: String? = null,
-        override var authMethod: AuthMethod,
+        override var authMethod: AuthMethod? = null,
     ) : AuthenticationUserContext
 
     object CoroutineUserContextHolder : UserContextHolder<UserContext> {