feat: add default role management functionality

- Introduced a new default role service and repository for managing default roles assigned to new members.
- Added command to set the default role through the bot's configuration.
- Implemented event handling to assign the default role to new guild members upon joining.
- Updated main application to include the new default role service in the bot's services.

internal/db/services/services.go

@@ -10,6 +10,7 @@ import (
 	"velox-bot/internal/db/services/twitch"
 	"velox-bot/internal/db/services/usersettings"
 	"velox-bot/internal/db/services/welcome"
+	"velox-bot/internal/db/services/defaultrole"
 )
 
 type Services struct {
@@ -22,11 +23,12 @@ type Services struct {
 	RPS           *rps.Service
 	Twitch        *twitch.Service
 	Welcome       *welcome.Service
+	DefaultRole   *defaultrole.Service
 }
 
 var Global *Services
 
-func NewServices(level *level.Service, levelSettings *levelsettings.Service, meeting *meeting.Service, schedule *schedule.Service, userSettings *usersettings.Service, projects *projects.Service, rps *rps.Service, twitchSvc *twitch.Service, welcomeSvc *welcome.Service) *Services {
+func NewServices(level *level.Service, levelSettings *levelsettings.Service, meeting *meeting.Service, schedule *schedule.Service, userSettings *usersettings.Service, projects *projects.Service, rps *rps.Service, twitchSvc *twitch.Service, welcomeSvc *welcome.Service, defaultRoleSvc *defaultrole.Service) *Services {
 	s := &Services{
 		Level:         level,
 		LevelSettings: levelSettings,
@@ -37,6 +39,7 @@ func NewServices(level *level.Service, levelSettings *levelsettings.Service, mee
 		RPS:           rps,
 		Twitch:        twitchSvc,
 		Welcome:       welcomeSvc,
+		DefaultRole:   defaultRoleSvc,
 	}
 	Global = s
 	return s