MM-32693: Use master when emoji_layer is invalidated (#16951)

We add a map which tracks invalidations to the emoji caches
and use master whenever a fresh item is fetched from DB.

https://mattermost.atlassian.net/browse/MM-32693

```release-note
NONE
```

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/sqlstore/emoji_store.go

@@ -4,6 +4,7 @@
 package sqlstore
 
 import (
+	"context"
 	"database/sql"
 	"fmt"
 
@@ -57,12 +58,12 @@ func (es SqlEmojiStore) Save(emoji *model.Emoji) (*model.Emoji, error) {
 	return emoji, nil
 }
 
-func (es SqlEmojiStore) Get(id string, allowFromCache bool) (*model.Emoji, error) {
-	return es.getBy("Id", id)
+func (es SqlEmojiStore) Get(ctx context.Context, id string, allowFromCache bool) (*model.Emoji, error) {
+	return es.getBy(ctx, "Id", id)
 }
 
-func (es SqlEmojiStore) GetByName(name string, allowFromCache bool) (*model.Emoji, error) {
-	return es.getBy("Name", name)
+func (es SqlEmojiStore) GetByName(ctx context.Context, name string, allowFromCache bool) (*model.Emoji, error) {
+	return es.getBy(ctx, "Name", name)
 }
 
 func (es SqlEmojiStore) GetMultipleByName(names []string) ([]*model.Emoji, error) {
@@ -146,10 +147,10 @@ func (es SqlEmojiStore) Search(name string, prefixOnly bool, limit int) ([]*mode
 }
 
 // getBy returns one active (not deleted) emoji, found by any one column (what/key).
-func (es SqlEmojiStore) getBy(what, key string) (*model.Emoji, error) {
+func (es SqlEmojiStore) getBy(ctx context.Context, what, key string) (*model.Emoji, error) {
 	var emoji *model.Emoji
 
-	err := es.GetReplica().SelectOne(&emoji,
+	err := es.DBFromContext(ctx).SelectOne(&emoji,
 		`SELECT
 			*
 		FROM