cut the runtime standard library into its own crate

If the runtime's components and the standard library gets cut into its own crate and published outside, it allows for anyone else having similar projects to easily integrate them and use them in their own works.

The components or libraries used can be set behind feature flags for customization, and enabled all by default for the runtime itself.

Another design decision that needs to be considered is to not directly add the defined functions into the Lua, and rather return them and have functionality to let the user add the components themselves. Another possibility for the sake of simplicity can be keeping the ability to add them all in a single function, with a prefix of choice.

No files, tests, or entry points are named. Start by locating the runtime components, standard-library definitions, and existing Lua function registration, then document the agreed crate boundary, feature-flag plan, and API for adding components before implementation begins.

Written by the indexing model from the issue text.