nautobot.utilities.filters.BaseFilterSet.FILTER_DEFAULTS does not allow models.TextField to use multi-value filtering

[lampwins]

Environment

• Python version: 3.9
• Nautobot version: 1.0.1

Steps to Reproduce

1. Create a model with a models.TextField
2. Create a filterset that exposes this field
3. Attempt to filter this field with multiple values

Expected Behavior

The filterset should implement the standard MultiValueCharFilter filter class capabilities, allowing for multi-value search using an OR condition.

Observed Behavior

The field only supports single-value search.

This is because nautobot.utilities.filters.BaseFilterSet.FILTER_DEFAULTS does not update the filter_class to use MultiValueCharFilter.

[glennmatthews]

Should be a pretty straightforward change to FILTER_DEFAULTS. I don't think this will impact the REST API, though it may impact FilterForms for the affected fields?