Maintenance: refactor servers updater code

- Require at least 80% of number of servers now to pass
- Each provider is in its own package with a common structure
- Unzip package with unzipper interface
- Openvpn package with extraction and download functions

internal/updater/providers/hidemyass/url.go

@@ -0,0 +1,44 @@
+package hidemyass
+
+import (
+	"strings"
+	"unicode"
+)
+
+func parseOpenvpnURL(url, protocol string) (country, region, city string) {
+	lastSlashIndex := strings.LastIndex(url, "/")
+	url = url[lastSlashIndex+1:]
+
+	suffix := "." + strings.ToUpper(protocol) + ".ovpn"
+	url = strings.TrimSuffix(url, suffix)
+
+	parts := strings.Split(url, ".")
+
+	switch len(parts) {
+	case 1:
+		country = parts[0]
+		return country, "", ""
+	case 2: //nolint:gomnd
+		country = parts[0]
+		city = parts[1]
+	default:
+		country = parts[0]
+		region = parts[1]
+		city = parts[2]
+	}
+
+	return camelCaseToWords(country), camelCaseToWords(region),
+		camelCaseToWords(city)
+}
+
+func camelCaseToWords(camelCase string) (words string) {
+	wasLowerCase := false
+	for _, r := range camelCase {
+		if wasLowerCase && unicode.IsUpper(r) {
+			words += " "
+		}
+		wasLowerCase = unicode.IsLower(r)
+		words += string(r)
+	}
+	return words
+}