added firebase and rudimentary leaderboard support

addons/godot-firebase/auth/providers/twitter.gd

@@ -0,0 +1,39 @@
+class_name TwitterProvider 
+extends AuthProvider
+
+var request_token_endpoint: String = "https://api.twitter.com/oauth/access_token?oauth_callback="
+
+var oauth_header: Dictionary = {
+    oauth_callback="",
+    oauth_consumer_key="",
+    oauth_nonce="",
+    oauth_signature="",
+    oauth_signature_method="HMAC-SHA1",
+    oauth_timestamp="",
+    oauth_version="1.0"
+}
+
+func _init(client_id: String,client_secret: String):
+    randomize()
+    set_client_id(client_id)
+    set_client_secret(client_secret)
+    
+    self.oauth_header.oauth_consumer_key = client_id
+    self.oauth_header.oauth_nonce = Time.get_ticks_usec()
+    self.oauth_header.oauth_timestamp = Time.get_ticks_msec()
+    
+    
+    self.should_exchange = true
+    self.redirect_uri = "https://twitter.com/i/oauth2/authorize?"
+    self.access_token_uri = "https://api.twitter.com/2/oauth2/token"
+    self.provider_id = "twitter.com"
+    self.params.redirect_type = "redirect_uri"
+    self.params.response_type = "code"
+    self.params.scope = "users.read"
+    self.params.state = str(randf_range(0, 1))
+
+func get_oauth_params() -> String:
+    var params: PackedStringArray = []
+    for key in self.oauth.keys():
+        params.append(key+"="+self.oauth.get(key))
+    return "&".join(params)