refactor(core): create instances' objects on commit

[CodyJasonBennett]

Solves a longstanding issue of OGL's constructor side-effects by creating instances' objects on commit mount instead of alongside instance creation. Instead, instances are descriptors that will create an OGL element once finalized and managed in the tree. This prevents GPU memory leaks that would arise when using suspense or concurrent features whenever instances are discarded and later recreated. Effectful constructors are not a good design, but this way, we work around them.