Add new blocks to GrapesJS builder

[volha-pivavarchyk]

Description:

Add additional blocks to the grapesjs builder for mjml emails.

The new blocks are:

1. sect 37 the section with 2 cells inside: 30% and 70%
2. text-sect the block with 2 text components, respectively for the heading and paragraph
3. grid-items the block of 2 components in row
4. list-items the list of 2 components

Related to the PR #11006

Steps to test:

1. Create new mjml email or choose an existing one
2. Open the grapesjs builder
3. New blocks here

[RCheesley]

@volha-pivavarchyk could you take a look at the conflict please? Many thanks!

[LordRembo]

I also have 2 PR's for updating GrapesJS in M5 and M4, these also fix the extra blocks in M4 too.

• one for the preset: Update grapesjs compatibility (Mautic 5) #49
• one Mautic (references the updated preset): Update grapesjs to more recent version (Mautic 5) mautic#13283

For M4, there's equivalent PR's linked from those M5 PR's

[LordRembo]

Ideally, we merge those updates and can close this one.

[LordRembo]

Ah, even better, looks like the addition of the blocks is already in the latest version of this preset. Probably via another PR?
@volha-pivavarchyk could you perhaps pull in the main or 5.x branch and confirm that this is the case?
Then we can close this PR

[volha-pivavarchyk]

@LordRembo sure I'll check. But I can do it only at the weekend.

[volha-pivavarchyk]

@LordRembo In fact, these changes have already been added. This PR can be closed

[volha-pivavarchyk]

The changes have been added