fix(apis_entities): only list possible properties in filterset form

[b1rger]

The filter related_properties listed all the existing properties, but
it makes more sense to only list the properties that can have the model
the filter filters as a subj or an obj.

Closes: #949

[gythaogg]

@b1rger In TibSchol I was asked to list the property either as forward or reverse as it applies to the entity type we are searching on.
For example the property composed by/author of between Work and Person
The related property field for Works will contain "composed by" and
the related property field for Persons with contain "author of"

If that makes sense for APIS in general then I'd recommend that as part of #949

When the subject and object are the same type, I displayed the text to show both forward and reverse text to select the property - but in Tibschol they want to see it as two different properties to filter the search better. IMO this is probably just a Tibschol specific requirement - need not be the default behaviour of APIS core.

[b1rger]

@b1rger In TibSchol I was asked to list the property either as forward or reverse as it applies to the entity type we are searching on. For example the property composed by/author of between Work and Person The related property field for Works will contain "composed by" and the related property field for Persons with contain "author of"

If that makes sense for APIS in general then I'd recommend that as part of #949

When the subject and object are the same type, I displayed the text to show both forward and reverse text to select the property - but in Tibschol they want to see it as two different properties to filter the search better. IMO this is probably just a Tibschol specific requirement - need not be the default behaviour of APIS core.

It makes sense to display the property with the name based on the entity we are filtering. I've tried to implement that and also added the possible property "targets". I'm not sure if it works as expected, the naming of properties in my test setups is a bit confusing

[b1rger]

(pls. rereview)

[gythaogg]

@b1rger yes - now the property is diplayed as it applies to the entity type as subject.
I created a Character to Place relation - lives in/has as a resident
As expected, in the Character search form I see lives in | place and,
in the Place search form I see has as a resident | character

When the Subject and Object are the same type of entity but have different forward and reverse property labels, such as this Character to Character relationship mother of/daughter of,
I see daughter of | character - which is the name_reverse. It's all right (name_forward would have also been fine), just checking if this the intended behaviour.

This might be because something is wrong with my setup and nothing to do with the pull request - but,

1. when I submit without selecting any property, I get

   Property matching query does not exist.

2. when I select a property and then search, I get

   PropertyFilter.filter() got an unexpected keyword argument 'triple_set_from_subj__prop'

[b1rger]

When the Subject and Object are the same type of entity but have different forward and reverse property labels, such as this Character to Character relationship mother of/daughter of, I see daughter of | character - which is the name_reverse. It's all right (name_forward would have also been fine), just checking if this the intended behaviour.

Thats up for discussion. I've now changed that to show name_forward / name_reverse | SubjObjType.

This might be because something is wrong with my setup and nothing to do with the pull request - but,

1. when I submit without selecting any property, I get
   > Property matching query does not exist.

2. when I select a property and then search, I get
   > PropertyFilter.filter() got an unexpected keyword argument 'triple_set_from_subj__prop'

I've fixed that.

[gythaogg]

Looks good to me!