[Table] Feature Request: Make it easier to provide custom data filters to MatTableDataSource

#### Bug, feature request, or proposal:

Feature Request

#### What is the expected behavior?

I'd like to be able to provide custom data filters.

#### What is the current behavior?

I can only affect how the free text search is executed

#### What are the steps to reproduce?

#### What is the use-case or motivation for changing an existing behavior?

I have a select box, name "Category" that contains a list of categories. User can select one category from this list. The table should filter to show only items in that category.

I also have free form text search and the user may or may not enter something there. (If the free text is empty, the datasource currently does no filtering.)

#### Which versions of Angular, Material, OS, TypeScript, browsers are affected?

All

#### Is there anything else we should know?

Thank you for the awesome framework!

Commencez par localiser l’implémentation de MatTableDataSource et son comportement existant de filtrage en texte libre. Déterminez comment un filtre de catégorie pourrait être fourni en complément d’une recherche textuelle facultative, puis vérifiez que le tableau peut filtrer selon la catégorie sélectionnée sans perturber le comportement lorsque le texte est vide.

Rédigé par le modèle d'indexation à partir du texte de l'issue.