fix: replace deprecated listenerCount
fix: promisify data in array
refactor: Connection.receive method
docs: add types for some Connection methods
test: improve Connection.receive cases
test: fix auth and cached cases

fix: generation of request id is moved to a separate function

fix: pass $req_id for auth and cached requests

feat: add module version to request data
fix: check array length to avoid creating holes
fix: move active requests to pending when connection has been closed
test: should buffer regular requests until the connection is ready
test: send pending execution requests after authorization

fix: check that callback is function
docs: describe Connection workflow

fix: execute regular requests only after authorization