[External Peripherals][Tracker] Support IPC-based external peripherals

[mortbopet]

This is a tracking commit for implementing support for IPC-based external peripherals. The idea behind this is to be able to define and implement protocols for:

1. Runtime handling of memory-mapped read/writes across a network connection to an external peripheral server.
2. Device discoverability, to provide symbols from an external peripheral to the Ripes assembler

The functionality will be developed on the following branch: https://github.com/mortbopet/Ripes/tree/external_io

• [External Peripherals] Define memory read/write protocol #162
• [External Peripherals] Define external peripheral read/write to Ripes memory #163
• [External Peripherals] Define device discoverability protocol #164