Add user blocking (#29028)

Fixes #17453

This PR adds the abbility to block a user from a personal account or
organization to restrict how the blocked user can interact with the
blocker. The docs explain what's the consequence of blocking a user.

Screenshots:


![grafik](https://github.com/go-gitea/gitea/assets/1666336/4ed884f3-e06a-4862-afd3-3b8aa2488dc6)


![grafik](https://github.com/go-gitea/gitea/assets/1666336/ae6d4981-f252-4f50-a429-04f0f9f1cdf1)


![grafik](https://github.com/go-gitea/gitea/assets/1666336/ca153599-5b0f-4b4a-90fe-18bdfd6f0b6b)

---------

Co-authored-by: Lauris BH <lauris@nix.lv>

models/organization/org.go

@@ -400,6 +400,7 @@ func DeleteOrganization(ctx context.Context, org *Organization) error {
 		&TeamUnit{OrgID: org.ID},
 		&TeamInvite{OrgID: org.ID},
 		&secret_model.Secret{OwnerID: org.ID},
+		&user_model.Blocking{BlockerID: org.ID},
 	); err != nil {
 		return fmt.Errorf("DeleteBeans: %w", err)
 	}

models/organization/team_user.go

@@ -30,14 +30,6 @@ func IsTeamMember(ctx context.Context, orgID, teamID, userID int64) (bool, error
 		Exist()
 }
 
-// GetTeamUsersByTeamID returns team users for a team
-func GetTeamUsersByTeamID(ctx context.Context, teamID int64) ([]*TeamUser, error) {
-	teamUsers := make([]*TeamUser, 0, 10)
-	return teamUsers, db.GetEngine(ctx).
-		Where("team_id=?", teamID).
-		Find(&teamUsers)
-}
-
 // SearchMembersOptions holds the search options
 type SearchMembersOptions struct {
 	db.ListOptions