[15.0][FIX] base_substate: track template on substate

[Saran440]

Move function _track_template() on base_substate_mixin to mail_thread
Currently, Email Template on Base Substate is not working.

Step to error:

1. Create base substate and add Email Template
2. Change substate to substate there is email template, it will not send email template.

[bosd]

I can confirm the issue.
Now everybode seems to be patching it in their *_substate module.

Test on this one are failling.
Unit tests on 15.0 branch are currently broken. Fix in: #733
Can you review the fix?

[bosd]

See comments in: #736 (review)

[github-actions]

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[bosd]

Just tested this locally. The error still exsists.

Traceback (most recent call last):
  File "/opt/odoo/custom/src/odoo/odoo/service/server.py", line 1260, in preload_registries
    registry = Registry.new(dbname, update_module=update_module)
  File "/opt/odoo/custom/src/odoo/odoo/modules/registry.py", line 87, in new
    odoo.modules.load_modules(registry, force_demo, status, update_module)
  File "/opt/odoo/custom/src/odoo/odoo/modules/loading.py", line 470, in load_modules
    processed_modules += load_marked_modules(cr, graph,
  File "/opt/odoo/custom/src/odoo/odoo/modules/loading.py", line 363, in load_marked_modules
    loaded, processed = load_module_graph(
  File "/opt/odoo/custom/src/odoo/odoo/modules/loading.py", line 198, in load_module_graph
    registry.setup_models(cr)
  File "/opt/odoo/custom/src/odoo/odoo/modules/registry.py", line 279, in setup_models
    model._prepare_setup()
  File "/opt/odoo/custom/src/odoo/odoo/models.py", line 2975, in _prepare_setup
    cls.__bases__ = cls.__base_classes
TypeError: Cannot create a consistent method resolution
order (MRO) for bases BaseModel, base, mail.thread, mail.activity.mixin, base.substate.mixin

[Saran440]

@bosd Thank you for checked.
Error because this model base.substate.mixin use mail.thread inherit and other module such as hr_expense_substate inherit mail.thread already
So, i deleted inherit and someone must inherit mail.thread itself if model not support