[11.x] Allow to set a name when registering a blade extension

[artrz]

This change allows to set a name when registering a blade extension, which can be used to override or control extensions added by third party packages.

[taylorotwell]

What is the benefit / use case?

[artrz]

@taylorotwell If packages extending the blade compiler like https://github.com/conedevelopment/blade-filters/blob/master/src/BladeFiltersServiceProvider.php could add a name it would be easy to override the registered callable.

[driesvints]

@artrz did you need a new review? Make sure to mark the PR as ready if you need one.

[artrz]

Thanks for the heads-up @driesvints

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!