when element is a revision, query the content block element revisions too

[i-just]

Description

If you have a Content Block field that’s inside of a Matrix field in the inline-editable blocks view mode and there are at least two “blocks” in that Matrix field, the Content Block elements are not retrieved correctly.

Steps to reproduce:

• clean 5.8.21 install with one site
• create a content block field myContentBlock with a plain text field in it plainText
• create a matrix field myMatrix with entry type withContentBlock, add myContentBlock field to it; view mode: inline-editable blocks; revisions: can be on or off - same results in both cases
• create a section mySection with entry type myEntryType, add myMatrix field to it (all default settings)
• create an entry in mySection, fill out the title, add two blocks to myMatrix, fill out the plainText field and fully save
• edit the first block, change the plainText field value and fully save
• view the first revision from the top - the plainText field in both blocks shows as empty

Fix: when the element is a revision, query for content block revisions.

Related issues

#18149