v3.3.0: Threadsafe-Support

- added Threadsafe Support for using the same or multiple incubed instances in different thread. (-DTHREADSAFE=true is per default, but can be deactivated for embedded devices if this does not apply.)
- refactored internal naming of ( in3_ctx_t -> in3_req_t ), public public apis did not change.
- add -experimental-flag to control usage of experimental features.
- add zksync API in JS and Java (experimental)
- fix signing for local testchains
- update autocomplete features for zsh 
- fix in3_weight-analyses
- fix heap memory corruption issue when configuring a nodelist with a duplicate address
- add signer-verification to zksync zk_sign
- add http-server optimizations using thread pools and supporting whitelists for allowed rpc-methods