Add support for BlockBundle 4.x

[wbloszyk]

Subject

@core23
After check #488 I think we can add support for BlockBundle 4.x. Can u check it?

I am targeting this branch, because it is PATCH.

[wbloszyk]

@core23 What do you think about it? Can we remove AbstractAdminBlockService?
It is not used in any place. You can find only method call like here:
https://github.com/sonata-project/SonataPageBundle/blob/master/src/Admin/BlockAdmin.php#L217-L238

@sonata-project/contribiutors
If we can do it like BC, then major upgrade for other sonata-project bundles will be much simpler.

[core23]

Suggested change

	{
	{
	$this->buildEditForm($formMapper, $block);

[wbloszyk]

This is AbstractAdminBlockService method, we should not change them. Self reference method make infinity loop.

[core23]

Looking at Travis, sonata-block 4 is never resolved

[wbloszyk]

@core23
I think other dependencies should be update first (like MediaBundle). What do you think about this changes? Should I work on this?

[core23]

@core23
I think other dependencies should be update first (like MediaBundle). What do you think about this changes? Should I work on this?

As said several time on many different issues. We had some major changes on the old core bundle and the block bundle. This changes can only be resolved with new major versions on our projects.

The main goal is still a new admin bundle major version. After that we can try to find a way for all other projects.

[SonataCI]

Could you please rebase your PR and fix merge conflicts?

[github-actions]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[core23]

We should not add this to the stable branch