chore(validation): move functions from constants

- Move validation functions from `internal/constants` to `internal/configuration/settings/validation`
- Concatenate all OpenVPN constants in `internal/constants/openvpn.go`

internal/updater/providers/surfshark/api.go

@@ -18,7 +18,8 @@ func addServersFromAPI(ctx context.Context, client *http.Client,
 		return err
 	}
 
-	hostToLocation := constants.SurfsharkHostToLocation()
+	locationData := constants.SurfsharkLocationData()
+	hostToLocation := hostToLocation(locationData)
 
 	const tcp, udp = true, true
 	for _, serverData := range data {

internal/updater/providers/surfshark/location.go

@@ -20,3 +20,12 @@ func getHostInformation(host string, hostnameToLocation map[string]models.Surfsh
 
 	return locationData, nil
 }
+
+func hostToLocation(locationData []models.SurfsharkLocationData) (
+	hostToLocation map[string]models.SurfsharkLocationData) {
+	hostToLocation = make(map[string]models.SurfsharkLocationData, len(locationData))
+	for _, data := range locationData {
+		hostToLocation[data.Hostname] = data
+	}
+	return hostToLocation
+}

internal/updater/providers/surfshark/remaining.go

@@ -6,7 +6,8 @@ import (
 
 // getRemainingServers finds extra servers not found in the API or in the ZIP file.
 func getRemainingServers(hts hostToServer) {
-	hostnameToLocationLeft := constants.SurfsharkHostToLocation()
+	locationData := constants.SurfsharkLocationData()
+	hostnameToLocationLeft := hostToLocation(locationData)
 	for _, hostnameDone := range hts.toHostsSlice() {
 		delete(hostnameToLocationLeft, hostnameDone)
 	}

internal/updater/providers/surfshark/zip.go

@@ -24,7 +24,8 @@ func addOpenVPNServersFromZip(ctx context.Context,
 		hostnamesDoneSet[hostname] = struct{}{}
 	}
 
-	hostToLocation := constants.SurfsharkHostToLocation()
+	locationData := constants.SurfsharkLocationData()
+	hostToLocation := hostToLocation(locationData)
 
 	for fileName, content := range contents {
 		if !strings.HasSuffix(fileName, ".ovpn") {