Easier way to override button

[VincentLanglet]

Subject

I am targeting this branch, because BC.

When you want to override a button label, or changing some design, you currently have to override the whole form actions, and copy paste all the logic.

With these new blocks, you can now override only one button without taking care bout the logic behind.
WDYT ?

Changelog

### Added
- New `block` twig in order to override the button display by the admin in the base_edit_form.

[dmaicher]

makes sense to me 👍

[franmomu]

Should we prefix these blocks with sonata_? looks like almost all of our blocks are prefixed

[VincentLanglet]

Should we prefix these blocks with sonata_? looks like almost all of our blocks are prefixed

The block formactions wasn't using the prefix.
I know in some other template (for show or list), there is a block field without the template too.

I would say it's better without the prefix, all of these template are inside the sonata project, there is no need to add this extra prefix. To me is kinda the same than prefixing all the method with sonata, like getSonataDatagrid().

[franmomu]

Based on sonata-project/dev-kit#205 (comment) looks like it was decided to add sonata_ prefix.

[VincentLanglet]

Based on sonata-project/dev-kit#205 (comment) looks like it was decided to add sonata_ prefix.

This was voted 5 year ago, and I checked and have difficulties to call this a standard when 90% of the blocks of the SonataAdmin code are not prefixed by sonata_ and not plan was made to respect this standard. :/

This is more consistent to me to respect the "empirical standard" of this project. Since almost all the block are already not prefixed. WDYT @sonata-project/contributors ?

[dmaicher]

I would say it's better without the prefix, all of these template are inside the sonata project, there is no need to add this extra prefix.

Yeah I would agree here. I don't see the benefit of those prefixes.