Allow non-admin users to delete review requests (#29057)

Fix #14459

The following users can add/remove review requests of a PR
- the poster of the PR
- the owner or collaborators of the repository
- members with read permission on the pull requests unit

(cherry picked from commit c42083a33950be6ee9f822c6d0de3c3a79d1f51b)

Conflicts:
	models/repo/repo_list_test.go
	tests/integration/api_nodeinfo_test.go
	tests/integration/api_repo_test.go
	shared fixture counts

routers/web/repo/issue.go

@@ -717,16 +717,12 @@ func RetrieveRepoReviewers(ctx *context.Context, repo *repo_model.Repository, is
 			tmp.ItemID = -review.ReviewerTeamID
 		}
 
-		if ctx.Repo.IsAdmin() {
-			// Admin can dismiss or re-request any review requests
+		if canChooseReviewer {
+			// Users who can choose reviewers can also remove review requests
 			tmp.CanChange = true
 		} else if ctx.Doer != nil && ctx.Doer.ID == review.ReviewerID && review.Type == issues_model.ReviewTypeRequest {
 			// A user can refuse review requests
 			tmp.CanChange = true
-		} else if (canChooseReviewer || (ctx.Doer != nil && ctx.Doer.ID == issue.PosterID)) && review.Type != issues_model.ReviewTypeRequest &&
-			ctx.Doer.ID != review.ReviewerID {
-			// The poster of the PR, a manager, or official reviewers can re-request review from other reviewers
-			tmp.CanChange = true
 		}
 
 		pullReviews = append(pullReviews, tmp)
@@ -1534,18 +1530,9 @@ func ViewIssue(ctx *context.Context) {
 	}
 
 	if issue.IsPull {
-		canChooseReviewer := ctx.Repo.CanWrite(unit.TypePullRequests)
+		canChooseReviewer := false
 		if ctx.Doer != nil && ctx.IsSigned {
-			if !canChooseReviewer {
-				canChooseReviewer = ctx.Doer.ID == issue.PosterID
-			}
-			if !canChooseReviewer {
-				canChooseReviewer, err = issues_model.IsOfficialReviewer(ctx, issue, ctx.Doer)
-				if err != nil {
-					ctx.ServerError("IsOfficialReviewer", err)
-					return
-				}
-			}
+			canChooseReviewer = issue_service.CanDoerChangeReviewRequests(ctx, ctx.Doer, repo, issue)
 		}
 
 		RetrieveRepoReviewers(ctx, repo, issue, canChooseReviewer)