Phase 1 "SVP"

What's Changed

• PR29 Extra reviews. by @john-michaelburke in #30
• Share constants by @jayvdb in #33
• [CPP-78][CPP-79]Navbar + TCP / File comms, disconnect, pause by @john-michaelburke in #32
• [CPP-108][CPP-79][CPP-54] Serial + Constants + Refresh Rates by @john-michaelburke in #36
• [CPP-37]Error panel by @jayvdb in #38
• [CPP-125] .cargo/config: Add rustc flags needed for macos by @jayvdb in #42
• [CPP-108]Move as many QML constants to Constants singleton as possible. by @john-michaelburke in #40
• [CPP-44] Observation tab by @jayvdb in #35
• remove need for dead_code annotations, fix rust-tests by @silverjam in #45
• Opengl merge by @john-michaelburke in #48
• [CPP-80]Add realtime delay when reading an SBPfile and pip cache to GA. by @john-michaelburke in #43

Full Changelog: 0.3.0...0.4.0