- Related: #7512

Load flags before creating logger so the logs path considers the
standalone flag.

Move the log file path definition to the function, otherwise it will
calculated during import and (most likely) before defining the
flags.STANDALONE value.

Create logger inside `run_frontend` right after knowing if we are
standalone or not.

- Resolves: #7512

Change KEYS_DIR for a function, so the path does not get defined on
import (and most likely) before the flags are defined.

Move the flags_dict call before the generate_zmq_certificates call.
Otherwise the standalone flag won't be set properly.

- Resolves: #7512

The new pyinstaller method will rule out the launcher, we need the
updater working inside bitmask client.

- Closes: #7291

otherwise, events are not correctly registered

- Resolves: #7149

Forward Twisted logs to logging and use logbook to handle logging logs.
Store the bitmask logs on the config folder.

Replace logging.getLogger with custom get_logger.
Remove some unneeded dependencies and reorder other.

We don't need to run the event server on the backend if we are running
from the standalone bundle since the launcher takes care of that.

- Related: #7126

If the events server is initialized in a different process than the backend,
the txzmq socket raises an "zmq.error.ZMQError: Interrupted system call"
exception during the events server initialization. Despite that, communication
seems to work flawlessly after the initialization.

Moving the events server initialization to the same process as the backend
causes the exception to not be raised during events server intialization.