Update: Allow tester to work without installation

- Use scripts and config from source folder
- Add paths to grammar files in build directory
- Hash key for flow token can be set using the configManager
- Conference server stateDir can be set using the configManager and will use std::filesystem::path instead of std::string
- Zrtp secrets not in binary folder anymore
- B2bua tester writes in writable dir instead of var

- CMake will not install the tester and its files anymore.
- CI Test without installation

(cherry picked from commit 2cd572db)