Block Bindings: Notify users of granular post meta edits in save panel

[artemiomorales]

What problem does this address?

When saving a post with a modified block binding, the save panel currently flags that the Post Meta has changed with the following:

However, this doesn't surface the individual changes that have occurred to the post meta, nor does it allow users to opt out of those edits in a piecemeal way.

What is your proposed solution?

We should instead revise the save panel so that it shows the following experience:

We can start with just showing what changes have been made, then later add the checkboxes.