Adds the functionality to receive CAT-Information (QRG, Mode, Power) via Websocket from Wavelog-Gate, instead of polling Wavelog over and over (which can cause performance-problems).

• Add Basic WebSocket-functionality to QSO-Form
• Error-Catching, captions, etc.
• Handling of formatted qrg and units
• testing "old roundtrip" as well as new functionality
• Adding the WebSocket functionality as well to Contest
• Adding the WebSocket functionality as well to DXCluster

to be fixed:

• Remember Websocket like other radio when switching pages

Needs WLGate >=V1.1.10 WavelogGate to test it. But: Should (and must) work also (the polling-way) with other 3rd-party-tools or older Versions of the Gate.

Important new Feature:

• if using the websocket, no key / url / whatever is needed to do CAT since Wavelog gets the CAT-Data directly from the client (without roundtrip via Wavelog). Localhost is doing the work.
• Affects ONLY CAT. If one wants to log - e.g. - wsjt-x QSOs via the Gate, key, url & Co. are still needed
• reduces the polling-load for CAT significant. Instead of fetching the CAT-Data from WL-Server every 3 seconds, WL-Page gets notified via the Websocket which QRG/Mode is on TRX
• Backwards-Compatibility. CAT-Data is posted (as before) to WL-Server. This PR is able to handle "classic CAT" as well as "Websocket"