Improve modularity by creating architecure guidelines

[mossmaurice]

Brief feature description

iceoryx is developed in several CMake packages that aim to be independent. Current state is there are cross dependencies between each of them and no architecture guidelines have been created so far.

Detailed information

Analysed iceoryx repository with Lattix Architect. Attached are the the dependecy structure matrix and the architecture metrixs of Lattix (commit b929aa8).

General

• Analyse Lattix
  • Dependecy structure matrix (DSM)
  • Architectual metrics
  • Conceptual architecture
• Namespaces & CMake package/library refactoring
• Add CMake target for quality level 5/playground features and move "maybe obsolote" constructs there
  • Add script to compare used namespaces to a whitelist in binary (nm -C myBinary -f posix with C++filt for demangling) to make sure no experimental/playground code is baked into releases
• RouDi modularisation RouDi modularisation #539
• Create architecture documentation
  • PlantUML or plain ASCII art?
  • Package view
  • Layer view
• Summarise guidelines and write a CI checker
  • Remove iox::helper namespace
• Create iceoryx_posh_core CMake target and address the @todo #590 in the CMake files
• Remove unused files and move quality level 2 files to a separate CMake package

Lattix Architect findings

• Move POSH specific errors from iceoryx_utils to iceoryx_posh Moved to Separate module specific errors from iceoryx_hoofs #1099
• roudi_gtest.hpp includes iceoryx_posh/internal/roudi_environment/roudi_environment.hpp
• Move RouDiEnvironment to test folder & namespace
• iceoryx_hoofs does not have a clear architecture and shall be better structured Move to Split iceoryx_hoofs into logical modules #1391

[mossmaurice]

FYI @dlo-86
Structure101 would be another option besides Lattix to analyse the architecture. However, I've had a glimpse at Lattix last Friday and found the DSM and its metrics quite helpful.