Allow external tools such as beezcli and ldb to run in parallel with speedb

[ofriedma]

Currently those tools can run in parallel with running db only when the db is being opened as secondary, which is preventing from doing write operations on top of it such as put. An idea to overcome this behaviour is to allow from the application to get securely operations from external tool and run them on top of the db. The application that already runs the db, could use a seperate thread that will listen on a separate socket and run from the application context the write operation which will allow to support any operation that is supported to be ran on a db by multiple threads