fix: allow text-columns to read a nested array value

[aSeriousDeveloper]

Description

When a Filament Text column reads a JSON attribute which contains a nested array, it throws an Array to string conversion exception.

I tracked down the issue to occuring in resources/views/columns/text-column.blade.php, where the arrayState is mapped and imploded. It goes through the given array and attempts to grab the value of each item. This works fine for single level arrays, as each value will be something stringable.

However, if one of the values was an array (such as storing a list of integers), then the implode fails.

There is already a check for Filament Enums with Labels for the text column, and collections can be coerced into strings. This PR adds an additional check for if the value being mapped for implosion is an array and if so, then encode it into json. Additionally, it adds a return type to the closure to enforce that the map returns a nullable string.

Visual changes

Short example of data:

Before the Fix

After the Fix

Functional changes

• Code style has been fixed by running the composer cs command.
• Changes have been tested to not break existing functionality.
• Documentation is up-to-date.