Try replacing tsc with tsup as build tool

[Janpot]

Running into trouble using modules from toolpad-app/src/** in the cli because they depend on ESM-only modules (execa, node-fetch@3, fractional-indexing, open-editor). The current setup makes it impossible to use these modules in a commonjs context (e.g. like the new CLI). tsc doesn't allow for transpiling dependencies. Proposing in this PR to move to tsup, which allows marking certain modules as noExternal. This can be used to bundle ESM only modules in the CLI.

• makes it possible to bundle ESM-only modules so we can use them in node.js
• increased performance
• Found a few missing dependencies in @mui/toolpad-components

Alternatives considered:

• do nothing, const { execa } = await import('execa') everywhere: Not always applicable, the burden is on the module consumer, creates a split-brain between different modules, extra overhead
• microbundle: slower, less batteries-included, less maintained, less popular
• babel: slow, less batteries-included
• @vercel/ncc: seems to be mainly focused on creating single file, node.js only focussed
• ?

https://npmtrends.com/microbundle-vs-tsdx-vs-tsup

[apedroferreira]

tsup definitely looks like the standard now, so this looks good!