Enhance support for extender attributes in DatasetAttributeProvider

[t1m0thyj]

Is your feature request related to a problem? Please describe.

As a ZE extender, I'd like the ability to add extra attributes to the Show Attributes webview for data sets. This is already possible but could be enhanced.

Describe the solution you'd like

1. Pass the attributes returned from the dataSet MVS API in the DsInfo context object.
2. Align all columns across multiple tables for both core and extender attributes.
3. Consider displaying a % character after the number for "Used Space" attribute.
4. Support numbers with thousands separators instead of highlighting them as strings.

Describe alternatives you've considered

As a workaround, extenders can cache data set attributes when listing them, so they can later be returned from fetchAttributes without making an additional API call.

Additional context

Related to zowe/zowex#625

[github-actions]

Thank you for raising this enhancement request.
The community has 90 days to vote on it.
If the enhancement receives at least 10 upvotes, it is added to our development backlog.
If it receives fewer votes, the issue is closed.

[lppedd]

I would also add that it would be cool to allow users to pick whether to display those attributes as an editor, or as a secondary side bar view. UX-wise I believe attributes are better served on the secondary side bar.

[vtushar06]

Hi @t1m0thyj and @JTonda,
I noticed this issue was recently unassigned,I would like to work on this.
Could you please assign this to me? I can start investigating the DatasetAttributeProvider logic immediately