New webhook trigger for receiving Pull Request review requests (#24481)

close https://github.com/go-gitea/gitea/issues/16321

Provided a webhook trigger for requesting someone to review the Pull
Request.

Some modifications have been made to the returned `PullRequestPayload`
based on the GitHub webhook settings, including:
- add a description of the current reviewer object as
`RequestedReviewer` .
- setting the action to either **review_requested** or
**review_request_removed** based on the operation.
- adding the `RequestedReviewers` field to the issues_model.PullRequest.
This field will be loaded into the PullRequest through
`LoadRequestedReviewers()` when `ToAPIPullRequest` is called.

After the Pull Request is merged, I will supplement the relevant
documentation.

models/issues/review_test.go

@@ -132,11 +132,22 @@ func TestGetReviewersByIssueID(t *testing.T) {
 			UpdatedUnix: 946684814,
 		})
 
-	allReviews, err := issues_model.GetReviewersByIssueID(issue.ID)
-	for _, reviewer := range allReviews {
-		assert.NoError(t, reviewer.LoadReviewer(db.DefaultContext))
-	}
+	allReviews, err := issues_model.GetReviewsByIssueID(issue.ID)
 	assert.NoError(t, err)
+	for _, review := range allReviews {
+		assert.NoError(t, review.LoadReviewer(db.DefaultContext))
+	}
+	if assert.Len(t, allReviews, 3) {
+		for i, review := range allReviews {
+			assert.Equal(t, expectedReviews[i].Reviewer, review.Reviewer)
+			assert.Equal(t, expectedReviews[i].Type, review.Type)
+			assert.Equal(t, expectedReviews[i].UpdatedUnix, review.UpdatedUnix)
+		}
+	}
+
+	allReviews, err = issues_model.GetReviewsByIssueID(issue.ID)
+	assert.NoError(t, err)
+	assert.NoError(t, issues_model.LoadReviewers(db.DefaultContext, allReviews))
 	if assert.Len(t, allReviews, 3) {
 		for i, review := range allReviews {
 			assert.Equal(t, expectedReviews[i].Reviewer, review.Reviewer)