[ADD] Addon: project_required_field_by_stage

[gfcapalbo]

reopening #1341 with original commits.
Added changes requested in that original MR-.

[ddejong-therp]

Code LGTM.
I've tested it, and run the tests as well.
All looks good.

[UrzaBlock]

Tested its functionality on runboat, and it does what it's supposed to do: When you have added fields in the Required Field section of a stage, a task that gets put in that stage will have those fields highlighted as required.

[NL66278]

Maybe I miss something, but I do not see why the inner loops are necessary. A project can only be in one stage, so why would this be wrong?

    @api.constrains("stage_id")
    def _check_stage_id_(self):
        for this in self:
            required_fields = this.stage_id.required_field_ids
            if not required_fields:
                continue
            for field in required_fields:
                if hasattr(this, field.name) and not getattr(this, field.name):
                    raise UserError(
                        _(  
                            "Field '%(field)s' is mandatory in stage '%(stage)s'."
                        )   
                        % ( 
                            {   
                                "field": field.display_name.split(" (")[0],
                                "stage": this.stage_id.display_name,
                            }   
                        )   
                    ) 

[ddejong-therp]

Ah yes I agree, I see that stage_id is a Many2one field

[gfcapalbo]

Every record has one stage. we only need to check mandatory fields for that one stage, not all stages every time. thank you @NL66278 , i will simplify this , by removing the loop.