Feature Request: add custom views on resource pages

[underdpt]

Hello,

Something I'm missing currently on Filament is the ability to add custom content on different points of the resource pages. For example, I would like to add the ability to add a button to export the table to excel with a button near the 'Delete all' button.

I think this can be easily acomplished with few lines of code, this is what I'm doing now:

1. On my resource ListRecords page, I add a new property:

class ListProveedores extends ListRecords
{
    /**
     * View to inject before the filters
     */
    public string $viewBeforeFilters = 'my.blade.view';

    public static $resource = ProveedorResource::class;
}

2. On list-records.blade.php (copied from vendor\filament\filament\resources\views\resources\pages\list-records.blade.php to resources\views\vendor\filament\resources\pages\list-records.blade.php for overloading):

    <x-filament::app-content class="space-y-4">
        <div class="items-center justify-between space-y-4 sm:flex sm:space-y-0">
            <div>
                @if ($this->canDelete())
                    <x-tables::delete-selected :disabled="! $this->canDeleteSelected()" />
                @endif
            </div>

            {{-- If we have something to show before the filters, inject here --}}
            @includeWhen($this->viewBeforeFilters, $this->viewBeforeFilters)

            <x-tables::filter :table="$this->getTable()" />
        </div>

So, you can create a new view, and put it on $viewBeforeFilters and it would be injected in that place, with access to the full Livewire component, properties and methods.

This can be extended to multiple places around the pages (as before and after header, footer, and so on), and also could be extended to allow to entirely change selected components on the page (for example you could use a custom filters component, or add more buttons to the actions header).

I would be able to add a PR for some starting points if this feature is something the maintainers would like to be added to Filament v1.