Add custom UDP connection & UDP Broadcast [Skybrush Support]

[seeul8er]

1. Allow users to add new UDP connections via the web interface or API manually. (Currently, UDP implementation requires registering a UDP connection via a UDP packet in WiFi client mode)
2. Users can specify a true UDP broadcast address when manually adding a new UDP connection
3. Rename the current UDP implementation to directional UDP
4. Report own MAC address via status JSON message
5. Listen for incoming broadcast UDP messages on port 14555 - This might interfere when 2. is set by the user
6. API to allow setting & resetting of static IP address in WiFi-Client mode. Fallback to DHCP assigned IP on failure

[4O6FPV]

This would be a wonderful addition to dronebrige to work with drone swarms more specifically for light shows. https://skybrush.io/modules/live/ It is possible to connect to a wifi and have it configure the IP but it would be much easier to know which IP was configured to exactly what UAS for debugging and other aspects of drone light shows. Also there is no issues with ESP-NOW other than needing one on each end but when you may be dealing with more that a couple I am not sure how well that would work plus it adds another esp when you would be connecting to a already established network for gps corrections.

[seeul8er]

A lot of effort has gone into the new release so far (see 2.0 branch). I implemented almost all of the above features already. Only thing missing is the support for static IP. A beta version will be available soon for testing. I think DroneBridge for ESP32 will then be compatible with Skybrush. All settings are available via a REST-API so configuration of the drones can be automated for the most part

[hi6otb]

@seeul8er Thanks. We will test it by using our show system.

[seeul8er]

RC1 of v2.0 is available: https://github.com/DroneBridge/ESP32/releases/tag/v2.0RC1