Add moveCookieToCategory mutation

Moving a cookie between categories previously required two sequential
updateCookieCategory mutations, which was not atomic and could leave
data in an inconsistent state if the second call failed. This adds a
dedicated moveCookieToCategory mutation that performs both updates in
a single transaction.

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/server/api/console/v1/graphql/cookie_banner.graphql

@@ -172,6 +172,9 @@ extend type Mutation {
     reorderCookieCategory(
         input: ReorderCookieCategoryInput!
     ): ReorderCookieCategoryPayload!
+    moveCookieToCategory(
+        input: MoveCookieToCategoryInput!
+    ): MoveCookieToCategoryPayload!
 }
 
 input CreateCookieBannerInput {
@@ -238,6 +241,12 @@ input CookieItemInput {
     description: String!
 }
 
+input MoveCookieToCategoryInput {
+    sourceCookieCategoryId: ID!
+    targetCookieCategoryId: ID!
+    cookieName: String!
+}
+
 type CreateCookieBannerPayload {
     cookieBannerEdge: CookieBannerEdge!
 }
@@ -281,3 +290,9 @@ type DeleteCookieCategoryPayload {
 type ReorderCookieCategoryPayload {
     cookieBanner: CookieBanner!
 }
+
+type MoveCookieToCategoryPayload {
+    sourceCookieCategory: CookieCategory!
+    targetCookieCategory: CookieCategory!
+    cookieBanner: CookieBanner!
+}