Add POSIX and Zephyr platform support for Ocre runtime

[kr-t]

Description

Add POSIX and Zephyr platform support for Ocre runtime

• Introduced core internal headers and source files for both POSIX and Zephyr platforms, including memory management, threading, mutexes, message queues, timers, and miscellaneous utilities.

• Implemented core functions for memory allocation and deallocation using malloc and free for POSIX, and k_malloc and k_free for Zephyr.

• Developed message queue functionalities with initialization, sending, and receiving capabilities for both platforms.

• Created thread management functions to handle thread creation, destruction, and execution for both environments.

• Added timer functionalities to support periodic and one-shot timers in the Ocre runtime.

• Implemented filesystem operations for Zephyr, including file opening, reading, and directory listing.

• Configured CMake build scripts for both platforms, ensuring proper linking and compilation of the Ocre runtime components.

• Integrated WAMR (WebAssembly Micro Runtime) support for both platforms, allowing for enhanced execution of WebAssembly modules.
  Also, please list any issue that this PR is intended to fix.

• Fixes issue ocre on linux - objectives, concerns - discussion #35

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• Code cleanup/refactoring
• This change requires a documentation update

How Has This Been Tested?

Tested on Zephyr's native_sim and u585, and Linux x86_64

Test Configuration (required):

• Host OS type, version, and arch: Ubuntu
• Developer Board make & model: STM32 U585

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[kr-t]

Both board on Zephyr (left) and Linux (right) work as expected