[MAJOR] Next-generation web interface and direct WebSocket support

[ehfd]

Reference the issue numbers and reviewers

Responsible: @ehfd @thelamer @PMohanJ

Main Issue aiming to solve:

• [META] Rewrite gst-web HTML5 interface frontend #108
• [META] WebTransport or Full WebSocket support / Investigate external libraries over GStreamer for transport protocols #48 (Focusing on WebSocket support, WebTransport to be spun off separately)

Issues and PRs to be solved (only close when this PR has been merged and code is present in main, not before that):

Web/Interface:

• When menu is open, CPU thread congestion from Vue causes choppy video and frame drop every second #159
• Instead of erroring with no audio server, restore server-side --disable_audio CLI option or automatically detect no PulseAudio server #147
• Support extended stylus or touch gestures #112
• Various issues related to clipboard relaying #100
• [META] Implement microphone, webcam, and other bidirectional capabilities #76 (mainly in WebRTC, feature parity with WebSockets required)
• Advanced authentication scenarios including URL parameters or JWT #25 (optional)
• Optionally show a touch keyboard in mobile browsers #22
• Support for International (AZERTY, etc.) keyboard layouts #9

Code quality and performance:

• Reduce reliance on external libraries / certain upstream packages are unmaintained #85
• system_metrics.py has a lot of things to be optimized using asyncio coroutines instead of the large blocks of for loops.
• Integrate asyncio coroutines rigorously across the whole backend code.
• Code duplicates between start_ws_pipeline and build_webrtcbin_pipeline, etc. in gstreamer_pipeline.py, most of these can be merged.
• Most constants defined in the backend code should be argparse options. Hard-coding is discouraged.
• Fix behavior of selkies-gstreamer-resize = "selkies_gstreamer.resize:entrypoint" in pyproject.toml.

Input:

• Keyboard and mouse are not working on Android Chrome/Firefox #177
• Joystick Interposer cannot be detected as a controller device in Steam Proton/Wine and RPCS3 #168
• Keyboard keystrokes continue to be held when packets are lost by congestion or unstable connection / Improve the last bit of keyboard latency overall while accommodating unstable connections #145 (integrate the reverse of the reverted commit 6a54bc7, except to take special consideration of asyncronous IO)

WebRTC:

• TURN-REST subproject does not conform to specifications #172
• [META] Optimize the WebRTC stack to the maximum #157 (partially)
• [META] Rust Components: WebRTCSink, WHIP/WHEP integration #79 (WHIP/WHEP doesn't provide DataChannels, so it is awkward in this context, integrate to SFU Server: Multiple users connected simultaneously, implement view-only password, isolated sessions #39 and just use the Rust components)
• [META] Implement chunked transport for WebRTC DataChannel / Image Clipboards #74
• SFU Server: Multiple users connected simultaneously, implement view-only password, isolated sessions #39

Media:

• Color is slightly incorrect from the GStreamer video converter #160
• Improve Opus: reduce NetEQ jitterbuffer & eliminate discontinuous audio artifacts from jitter with Opus + RED #153 (optional, this is in WebRTC but applicable to WebSockets too)
• Achieve higher efficiency and quality in low-bandwidth and high-latency environments #152
• [META] Codec improvement and additional support including AV1/H.265, Intel/AMD GPU encoding support #34

CI/CD or Maintenance:

• Request to retrieve the latest version of selkies-gstreamer returns a 403 #180 (Rewire selkies-gstreamer references to selkies)
• added debian 12 dockerfiles and deb packages #163
• Divide Dockerfile to various containers in selkies-vdi #161 (optional, follow up in another PR)
• Integrate selkies-gstreamer to Jupyter and Coder (just like noVNC) #64
• [META] Use the Conda package management system or AppImage for rootless portable installations #63
• [META] Use automated testing / Add .deb/.rpm/pacman packages #58
• [META] ARM, mobile/embedded devices, and IBM POWER ppc64le #50 (Focus on ARM)

Explain relevant issues and how this pull request solves them

New updated web interface and direct WebSocket support, with other improvements.

Describe the changes in code and its dependencies and justify that they work as intended after testing

New updated web interface and direct WebSocket support, with countless other improvements.