[Admin] Sorting title does not work when content type has another title field

[clem]

Details

Question	Answer
Relevant Bolt Version	master
Install type	Composer install
BC Break	no
PHP version	7.4
Web server	Built-in

Reproduction

If you're filing a bug, please describe how to reproduce it. Include as much
relevant information as possible, such as:

Bug summary

* When I have a content type with two `title` fields (one at the root level, and another in a `set` field)
* the sorting on the admin listing page is not relevant

Specifics

* I am using Bolt 5.1.18
* It was installed with `composer create-project bolt/project bolt-issues`
* I am using Firefox 108.0.1 
* I have also checked with Safari

Steps to reproduce

* Install a fresh Bolt project
* Update the product content type to add a custom set field with a `title` sub-field:

        my_custom_set:
            type: set
            fields:
                title: 
                    type: text
                    label: 'My custom set title'
                description:
                    type: redactor
                    label: 'My custom set description'

* Go on the products admin and update some products to set `title`s in the custom set field
* Sort by "Title"
* Here's an example of what it looks like:

Expected result

* I expect the products to be sorted by their title, and not by the custom set's title

Actual result

* Products are sorted by their titles (main title and custom set's title)

Thanks a lot 🙏