Upgrades broken

[carlcsaposs-canonical]

Upgrades broken by #93

Calls to workload.enable() and workload.disable() appear on main

mysql-router-operator/src/workload.py

Lines 398 to 402 in 557f884

	self.disable()
	super().upgrade(unit=unit, tls=tls)
	if enabled:
	logger.debug("Re-enabling MySQL Router service after upgrade")
	self.enable(tls=tls, unit_name=unit.name)

but workload.enable() and workload.disable() removed in #93

Causes error:

unit-mysql-router-2: 11:25:29 ERROR unit.mysql-router/2.juju-log upgrade-version-a:5: Uncaught exception while in charm code:
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/./src/machine_charm.py", line 117, in <module>
    ops.main.main(MachineSubordinateRouterCharm)
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/venv/ops/main.py", line 441, in main
    _emit_charm_event(charm, dispatcher.event_name)
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/venv/ops/main.py", line 149, in _emit_charm_event
    event_to_emit.emit(*args, **kwargs)
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/venv/ops/framework.py", line 344, in emit
    framework._emit(event)
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/venv/ops/framework.py", line 841, in _emit
    self._reemit(event_path)
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/venv/ops/framework.py", line 930, in _reemit
    custom_handler(event)
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/src/abstract_charm.py", line 252, in reconcile
    self._upgrade.upgrade_unit(
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/src/machine_upgrade.py", line 150, in upgrade_unit
    workload_.upgrade(unit=self._unit, tls=tls)
  File "/var/lib/juju/agents/unit-mysql-router-2/charm/src/workload.py", line 398, in upgrade
    self.disable()
AttributeError: 'AuthenticatedSocketWorkload' object has no attribute 'disable'

[github-actions]

https://warthogs.atlassian.net/browse/DPE-4179

[carlcsaposs-canonical]

@taurus-forever FYI

[shayancanonical]

resolved in #119 and added tests in #135