chore(all): provider to servers map in allServers

- Simplify formatting CLI
- Simplify updater code
- Simplify filter choices for config validation
- Simplify all servers deep copying
- Custom JSON marshaling methods for `AllServers`
- Simplify provider constructor switch
- Simplify storage merging
- Simplify storage reading and extraction
- Simplify updating code

internal/models/getservers.go

@@ -4,108 +4,17 @@ import (
 	"net"
 )
 
-func (a AllServers) GetCopy() (servers AllServers) {
-	servers = a // copy versions and timestamps
-	servers.Cyberghost.Servers = a.GetCyberghost()
-	servers.Expressvpn.Servers = a.GetExpressvpn()
-	servers.Fastestvpn.Servers = a.GetFastestvpn()
-	servers.HideMyAss.Servers = a.GetHideMyAss()
-	servers.Ipvanish.Servers = a.GetIpvanish()
-	servers.Ivpn.Servers = a.GetIvpn()
-	servers.Mullvad.Servers = a.GetMullvad()
-	servers.Nordvpn.Servers = a.GetNordvpn()
-	servers.Perfectprivacy.Servers = a.GetPerfectprivacy()
-	servers.Privado.Servers = a.GetPrivado()
-	servers.Pia.Servers = a.GetPia()
-	servers.Privatevpn.Servers = a.GetPrivatevpn()
-	servers.Protonvpn.Servers = a.GetProtonvpn()
-	servers.Purevpn.Servers = a.GetPurevpn()
-	servers.Surfshark.Servers = a.GetSurfshark()
-	servers.Torguard.Servers = a.GetTorguard()
-	servers.VPNUnlimited.Servers = a.GetVPNUnlimited()
-	servers.Vyprvpn.Servers = a.GetVyprvpn()
-	servers.Windscribe.Servers = a.GetWindscribe()
-	return servers
-}
-
-func (a *AllServers) GetCyberghost() (servers []Server) {
-	return copyServers(a.Cyberghost.Servers)
-}
-
-func (a *AllServers) GetExpressvpn() (servers []Server) {
-	return copyServers(a.Expressvpn.Servers)
-}
-
-func (a *AllServers) GetFastestvpn() (servers []Server) {
-	return copyServers(a.Fastestvpn.Servers)
-}
-
-func (a *AllServers) GetHideMyAss() (servers []Server) {
-	return copyServers(a.HideMyAss.Servers)
-}
-
-func (a *AllServers) GetIpvanish() (servers []Server) {
-	return copyServers(a.Ipvanish.Servers)
-}
-
-func (a *AllServers) GetIvpn() (servers []Server) {
-	return copyServers(a.Ivpn.Servers)
-}
-
-func (a *AllServers) GetMullvad() (servers []Server) {
-	return copyServers(a.Mullvad.Servers)
-}
-
-func (a *AllServers) GetNordvpn() (servers []Server) {
-	return copyServers(a.Nordvpn.Servers)
-}
-
-func (a *AllServers) GetPerfectprivacy() (servers []Server) {
-	return copyServers(a.Perfectprivacy.Servers)
-}
-
-func (a *AllServers) GetPia() (servers []Server) {
-	return copyServers(a.Pia.Servers)
-}
-
-func (a *AllServers) GetPrivado() (servers []Server) {
-	return copyServers(a.Privado.Servers)
-}
-
-func (a *AllServers) GetPrivatevpn() (servers []Server) {
-	return copyServers(a.Privatevpn.Servers)
-}
-
-func (a *AllServers) GetProtonvpn() (servers []Server) {
-	return copyServers(a.Protonvpn.Servers)
-}
-
-func (a *AllServers) GetPurevpn() (servers []Server) {
-	return copyServers(a.Purevpn.Servers)
-}
-
-func (a *AllServers) GetSurfshark() (servers []Server) {
-	return copyServers(a.Surfshark.Servers)
-}
-
-func (a *AllServers) GetTorguard() (servers []Server) {
-	return copyServers(a.Torguard.Servers)
-}
-
-func (a *AllServers) GetVPNUnlimited() (servers []Server) {
-	return copyServers(a.VPNUnlimited.Servers)
-}
-
-func (a *AllServers) GetVyprvpn() (servers []Server) {
-	return copyServers(a.Vyprvpn.Servers)
-}
-
-func (a *AllServers) GetWevpn() (servers []Server) {
-	return copyServers(a.Wevpn.Servers)
-}
-
-func (a *AllServers) GetWindscribe() (servers []Server) {
-	return copyServers(a.Windscribe.Servers)
+func (a AllServers) GetCopy() (allServersCopy AllServers) {
+	allServersCopy.Version = a.Version
+	allServersCopy.ProviderToServers = make(map[string]Servers, len(a.ProviderToServers))
+	for provider, servers := range a.ProviderToServers {
+		allServersCopy.ProviderToServers[provider] = Servers{
+			Version:   servers.Version,
+			Timestamp: servers.Timestamp,
+			Servers:   copyServers(servers.Servers),
+		}
+	}
+	return allServersCopy
 }
 
 func copyServers(servers []Server) (serversCopy []Server) {