metadata and section-metadata blocks are not getting copied correctly in Library

[aishwaryamathuria]

I was looking into the following Jira issue wherein the metadata and section-metadata blocks are not getting copied correctly.
Currently on copying we are getting the columns block authored in https://main--milo--adobecom.hlx.page/docs/library/blocks/section-metadata with extra column headings and notes.
This would require authors to delete the extra heading, fields and rename the block to metadata/section-metadata.
Based on the current implementation of the way library is handled we have following approaches to fix this issue.

Approach 1:

We continue to copy the columns block but after copying we replace the table header with correct block name (section-metadata / metadata) and modify the table to remove column headings and notes

Approach 2:

We can re-author the section-metadata docx (removing extra data) and move the detailed docx to kitcken-sink. In library we can continue to copy the columns and replace the block name with (section-metadata / metadata)

Approach 3:

Hitting copy on metadata / section metadata should only copy a table with block name and empty row and author can add new rows with expected values from the documentation.

@chrischrischris @auniverseaway @vhargrave @fullcolorcoder Could you provide your inputs on the same based on the current expectation on what section-metadata/metadata copy should add on the docx?

[vhargrave]

There is no metadata block we're providing in the library, so I don't think you need to worry about that.
Regarding the section-metadata, I'm actually wondering if we want to stop "ignoring" the section-metadata when copying content from the library. When authoring the library we usually shouldn't be setting the section metadata, unless it's really necessary, in which case we probably should give authors the option to copy it too (tabs as an example)
Thoughts?

[chrischrischris]

The issue with the section-metadata library page is that it's not authored to be a library page, it's a page to show different types of metadata. We need to change the page to be tailored to the library specifically for section-metadata.

This PR adds a library-metadata block which I believe we should adapt to be able to specify what can be included / excluded from being copied in a section (as well as keywords, possible title change etc)