Use forge from db (#1417)

This is the first step towards support for multiple forges (#138). It
inserts a forge using the currently existing env varaibles into db and
uses this forge from db later on in all places of the code.

closes #621

addresses #138 

# TODO
- [x] add forges table
- [x] add id of forge to repo
- [x] use forge of repo
- [x] add forge from env vars to db if not exists
- [x] migrate repo.ForgeID to the newly generated forge
- [x] support cache with forge from repo
- [x] maybe add forge loading cache? (use LRU cache for forges, I expect
users to have less than 10 forges normally)

---------

Co-authored-by: qwerty287 <80460567+qwerty287@users.noreply.github.com>

server/web/config.go

@@ -39,12 +39,20 @@ func Config(c *gin.Context) {
 		).Sign(user.Hash)
 	}
 
+	// TODO: remove this and use the forge type from the corresponding repo
+	mainForge, err := server.Config.Services.Manager.ForgeMain()
+	if err != nil {
+		log.Error().Err(err).Msg("could not get main forge")
+		c.AbortWithStatus(http.StatusInternalServerError)
+		return
+	}
+
 	configData := map[string]any{
 		"user":               user,
 		"csrf":               csrf,
 		"version":            version.String(),
 		"skip_version_check": server.Config.WebUI.SkipVersionCheck,
-		"forge":              server.Config.Services.Forge.Name(),
+		"forge":              mainForge.Name(),
 		"root_path":          server.Config.Server.RootPath,
 		"enable_swagger":     server.Config.WebUI.EnableSwagger,
 	}