Add renderer drawing revision rectangles

[kyasbal]

This PR adds renderers specific to draw diamond shaped dots for events.

This PR depends #463 and includes the changes introduced in #463. This would be merged after rebasing this on #463 once the parent review is done.

[gemini-code-assist]

Summary of Changes

Hello @kyasbal, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly upgrades the timeline's rendering capabilities by introducing a comprehensive WebGL-based system for displaying and interacting with timeline revisions. The changes focus on improving rendering performance and enabling advanced visual effects through GPU acceleration, laying the groundwork for a more dynamic and responsive user interface.

Highlights

• WebGL Utilities: Introduced a new WebGLUtil class to centralize common WebGL operations such as compiling and linking shaders, loading textures, and parsing BMFont configurations. This streamlines WebGL setup and resource management.
• Timeline Hit Testing: Added TimelineHitTestSharedResource to implement efficient WebGL-based hit testing for timeline elements. This uses a framebuffer object (FBO) and a texture to render an index map, allowing quick identification of elements at specific screen coordinates.
• Revision Renderer: Implemented TimelineRevisionsRenderer and TimelineRevisionsSharedResources to render timeline revisions using WebGL. This renderer leverages instanced rendering for performance, managing Vertex Array Objects (VAOs) and Vertex Buffer Objects (VBOs) for revision data and dynamic highlight states.
• GLSL Shaders: New GLSL shaders (revision-v2.vertex.glsl, revision-v2.color-fragment.glsl, revision-v2.hittest-fragment.glsl, revision-v2.shared.glsl, v2.shared.glsl) were added to support the WebGL rendering of timeline revisions, including color rendering, hit testing, and shared uniform block definitions.
• Shared Renderer Resources: The TimelineRendererSharedResource was updated to manage MSDF (Multi-channel Signed Distance Field) textures for numbers and icons, along with their BMFont configurations, and a shared Uniform Buffer Object (UBO) for global view state parameters.

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[gemini-code-assist]

Code Review

This pull request introduces a new WebGL-based renderer for timeline revisions, which is a significant feature. The implementation is comprehensive, covering WebGL utilities, shared resources, specific renderers for revisions, and the corresponding GLSL shaders. The code is well-structured, but I've found a critical issue with UBO layout padding that would cause rendering artifacts, along with several opportunities for performance improvements and increased code clarity. My review includes a fix for the critical bug, suggestions to parallelize asynchronous operations, optimizations for data lookups, and recommendations to replace magic numbers with named constants for better maintainability.