gl: Refactor shader compilation

[AniLeo]

More work towards the OpenGL render, refactors all shader compilation code into using the unique gl::glsl::shader path

gl: Refactor shader compilation

• Refactors the three existing shader compilation paths into an unique gl::glsl::compile path
• GLVertexProgram: Removes unused interleaved var
• gl::glsl::shader: Stores shader source on struct for usage in other places
• gl::glsl::shader: Remove recreate() and partial constructors

gl: Refactor shader type usage

• Removes duplicated type in gl::glsl::shader in favor of Common glsl::program_domain types: stores program_domain in the gl::glsl::shader struct and converts to OpenGL specific GLenum when needed

gl: Only log shaders if g_cfg.video.log_programs is enabled