Polish newly merged core+sophus2+cmake project

[strasdat]

Initial PR merging sophus2 and farm-ng-core in: #105

• sort cpp/sophus2 better into existing directory structure
  refactor: sort sophus more consistent into directory structure #113
• docs:
  • revive/merge docs
• review all scripts in top level folder and see whether they are still needed
• dependency management
  • document venv
    refactor: sort sophus more consistent into directory structure #113
  • merge / simply venv build scripts
    refactor: sort sophus more consistent into directory structure #113
  • merge Eigen/format submodules with venv build process
• cmake
  • flatten directory structure
  • merge cmake/scripts with infra/scripts
• CI tooling
  • revive clang-tidy
  • asan
  • compile time analysis
• Merge geometric protos in sophus namespace with newly introduced protos in farm_ng namespace.
  • This will break log formats in downstream projects and should be done on a as needed basis only.
• use specialization instead of ADL for proto conversion
  to enable more general purpose event logger and playback tools (e.g. such tool do not need to include all proto_conv headers, but only the definition of the toProto / fromProto function template)
  • proto_conv #135