[p5.strands] Aliasing GLSL's mix as lerp

[lukeplowden]

Increasing access

This change will increase access to p5.strands and shader programming in general by bridging the gap between core p5.js code and strands code.

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• Build process
• Unit testing
• Internationalization
• Friendly errors
• Other (specify if possible)

Feature enhancement details

As mentioned in #7849, GLSL has a built in function mix, which does the same operation as p5.js' lerp. We want to alias mix as lerp so that it can be used in shaders, as part of an effort to make more p5.js functions work as expected within p5.strands

[lukeplowden]

Hey @LalitNarayanYadav, I'm redirecting you to this sub issue of #7849 so you can implement this! Thank you for taking this on, and please @ me for any questions. Make a comment on this issue too, so that I can assign you to it.