Separate platform-specific modules from `eavmlib`

[bettio]

eavmlib is a mixture of:

• utility modules (e.g. avm_pubsub)
• atomvm extension modules (e.g. atomvm module)
• generic hardware abstraction modules (e.g. uart, gpio, etc...)
• hardware specific modules (esp, pico, etc...)

1. As a bare minimum plan, hardware specific modules should be moved away from eavmlib, since it doesn't make sense to ship ESP32 module on RP2040.
2. eventually all the 4 categories of modules should be separated into different libraries, or at least a generic HAL library should be created, so we don't ship SPI code on emscripten platform.