Do some performance optimize for issues list and view issue/pull (#29515)

This PR do some performance optimzations.

- [x] Add `index` for the column `comment_id` of `Attachment` table to
accelerate query from the database.
- [x] Remove unnecessary database queries when viewing issues. Before
some conditions which id = 0 will be sent to the database
- [x] Remove duplicated load posters 
- [x] Batch loading attachements, isread of comments on viewing issue

---------

Co-authored-by: Zettat123 <zettat123@gmail.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/models/issues/comment.go b/models/issues/comment.go
index e37f844b5c..6f65a5dbbc 100644
--- a/models/issues/comment.go
+++ b/models/issues/comment.go
@@ -673,7 +673,8 @@ func (c *Comment) LoadTime(ctx context.Context) error {
 	return err
 }
 
-func (c *Comment) loadReactions(ctx context.Context, repo *repo_model.Repository) (err error) {
+// LoadReactions loads comment reactions
+func (c *Comment) LoadReactions(ctx context.Context, repo *repo_model.Repository) (err error) {
 	if c.Reactions != nil {
 		return nil
 	}
@@ -691,11 +692,6 @@ func (c *Comment) loadReactions(ctx context.Context, repo *repo_model.Repository
 	return nil
 }
 
-// LoadReactions loads comment reactions
-func (c *Comment) LoadReactions(ctx context.Context, repo *repo_model.Repository) error {
-	return c.loadReactions(ctx, repo)
-}
-
 func (c *Comment) loadReview(ctx context.Context) (err error) {
 	if c.ReviewID == 0 {
 		return nil