add PiP Side Camera

[prabhaavp]

Description

Adds a Picture-in-Picture side camera preview bubble on the onroad screen when turn signals or blind spot detection (factory BSM or V-ASM) are active.

Renders circular driver camera crops using a custom GLSL shader. Includes configuration tools in Galaxy, backend API endpoints, settings layout definitions, and parameters (PIPPreviewEnabled, PIPPreviewMask, PIPPreviewShowOnBlinker, PIPPreviewShowOnBSM).

---

Verification

• Conducted extended on-device testing during real-world driving to verify trigger logic with turn signals and blind spot monitors.
• Monitored process resource utilization using htop on device while active; observed no stutters or unexpected CPU/RAM spikes.
• Checked overall codebase consistency and verified configuration flow in Galaxy.
• Ran device settings layout tests via pytest.

---

Concerns

• Dev environment pytest setup was failing on unrelated changes [check discord for error], which made it less ideal to add more tests. Relied heavily on on-device verification / performance.
• Requesting reviewer feedback / changes on potential code optimizations.
• To allow toggle to work by default, a default config value for param is provided so toggle does not need to be gated to try the feature / avoid common confusion why toggle is greyed out. Toggle is not gated for off road either as it's not necessary at all. Live changes work and reflect.