Purpose:
--------
When the property field is added into a form view, the "add a property"
button is shown by default.
However, most of the time the users won't add properties when opening a
form view, making this button take up space for nothing.
To alleviate this issue, commit [1] added an option that allows to hide
this button, and added actions to allow adding properties from the cog
menu instead.
Now that properties are being added into several views, one would like
this "add properties" button to be hidden by default, and show an entry
in the cogmenu allowing add properties by default, without needing to
create an action for every view using a property field.
Therefore, a new static action "Add Properties" has been added in the form
controller that is available if a properties field has been encountered
during the parsing of the form view's arch.
The "hideAddButton" has been changed into "showAddButton" and now allows
to show the "Add a Property" by default.
Task-3458627
[1]: https://github.com/odoo/odoo/commit/1f80810e39f811122a65e11cd8cac99aa39a7960
Part-of: odoo/odoo#137589
Adrien Schoffeniels
2d7a49dab1