Add warnings at build about access to globals

Nobody has claimed this yet.

The same way we see is done in [lava-moat examples](https://github.com/LavaMoat/lavamoat-browserify-examples), the [lavamoat](https://github.com/lavamoat/lavamoat-browserify) tool uses [tofu](https://github.com/lavamoat/sesify-tofu), which can generate a file that emits every global variable that a module obviously requires to operate.

Many snap developers have found themselves hitting points where a module would not fully operate under SES because of some deeply-hidden `setTimeout` or `Uint8Array` in one of their dependencies.

We could add a [tofu](https://github.com/lavamoat/sesify-tofu) pre-process to the build step, and proactively warn developers when a module had some global requirement, and link to a blog post demonstrating how to do it.

For example:
- [Adding globals to plugin endowments](https://github.com/MetaMask/metamask-snaps-beta/pull/134)
- [Adding a whole module to plugin endowments](https://github.com/MetaMask/metamask-snaps-beta/pull/136)

Ref: https://github.com/MetaMask/snaps-cli/pull/46

Read the tofu and LavaMoat examples first, then inspect the snaps build step referenced in the issue and the related snaps-cli pull request. Define how tofu output should be integrated and how warnings should point developers to the globals or modules needing endowments; done means builds proactively report those requirements with the intended guidance link.

Written by the indexing model from the issue text.