Add the standard search bar to the SelectPerson dialog

[stevenyoungs]

Add the standard search bar to the SelectPerson dialog

[stevenyoungs]

This is draft, pending user feedback from the forum. See the post Adding Search Bar to Select Person Dialog

[stevenyoungs]

Requires PR #1869 to be merged first

[stevenyoungs]

This is now ready for review.
The image below shows what adding a Father now looks like by default:

With #1869 is applied the filter becomes "Gender is"
The user experience for adding a Mother is similar, but the text defaults to Female
When adding a child, there is no default filter applied.

The user can click Clear to remove the default filter. All people are then shown. This allows the "Show All" toggle to be removed.
Using the search bar filter removes the ambiguity of whether the search bar or default filter should take precedence; they are now one and the same.

This was in part made possible by using the search bar filter instead of FastMaleFilter and FastFemaleFilter classes. Whilst the class names imply they are fast, when measured in gramps 6.0 performance was essentially the same.
Tests were carried out using a 15 generation tree containing 32,767 individuals. The tree was created using [Gedfan](https://www.tamurajones.net/[GedFan](https://www.tamurajones.net/GedFan.xhtml)

Using FastMaleFilter: 5 runs
PersonTreeModel rebuild_data 5.990803000051528 sec
PersonTreeModel rebuild_data 6.005976999993436 sec
PersonTreeModel rebuild_data 6.018445700057782 sec
PersonTreeModel rebuild_data 6.21256649994757 sec
PersonTreeModel rebuild_data 5.999285100027919 sec

Using search bar filter: 5 runs
PersonTreeModel rebuild_data 6.127757900045253 sec
PersonTreeModel rebuild_data 5.954343599965796 sec
PersonTreeModel rebuild_data 6.565670200041495 sec
PersonTreeModel rebuild_data 6.176048699999228 sec
PersonTreeModel rebuild_data 6.132094100001268 sec

[Nick-Hall]

This looks like a better approach.

[stevenyoungs]

The bug fix part of #1865 has been combined into this PR

[Nick-Hall]

Rebased.