Reduce field storage size by passing max length

Signed-off-by: Knut Ahlers <knut@ahlers.me>

pkg/database/struct.go

@@ -2,13 +2,13 @@ package database
 
 type (
 	StreakMeta struct {
-		Name  string `gorm:"primaryKey"`
-		Value string
+		Name  string `gorm:"primaryKey;size:128"`
+		Value string `gorm:"size:128"`
 	}
 
 	StreakUser struct {
 		TwitchID      uint64 `gorm:"primaryKey"`
-		Username      string
+		Username      string `gorm:"size:128"`
 		StreamsCount  uint64
 		CurrentStreak uint64
 		MaxStreak     uint64