Add trigger sync to avalon plugin for Hiero

[mre7a]

We trigger the Sync to Avalon action at the end of the publish process, as it is not done automatically. This will update tools attributes on the created shots.

To test it, you should:

• Clone this repo and change OPENPYPE_CUSTOM_PLUGINS environment in local openpype settings.
• Open Hiero in this context: project: TEST_OP2_PUB_23_7, shot: Editorial, task: confo
• Select the shot 904_0090 in timeline and publish (you can publish each shot just once)

[BenSouchet]

Closed since I simpler method has been used for now.