Metadata blocks available to only one collection (and possibly all metadata blocks) are not available when editing dataset templates created before the metadata blocks were added

[jggautier]

What steps does it take to reproduce the issue?

• When does this issue occur?
  When editing a dataset metadata template that was created before the metadata block was made available to the collection.

• Which page(s) does it occurs on?
  On the page where you can edit the metadata of a template that was created before the metadata block was added to the collection (From the Dataverse collection page, click Edit > Dataset Templates > Metadata)

• What happens?
  Metadata blocks that were added after the dataset metadata template was created are not there when editing the dataset metadata template.

  And if the template is the collection's default template, when depositors create a dataset, the accordion for the metadata block appears empty when the accordion is open (see screenshot below).

• To whom does it occur (all users, curators, superusers)?
  Superusers, anyone editing the Dataverse collection

• What did you expect to happen?
  The new metadata block appears in the metadata template

Which version of Dataverse are you using?
v5.10.1

Any related open or closed issues to this bug report?
None that I could find

Screenshots:
Because the template that was created before the metadata block was added is the default template for the collection, when depositors create a dataset, the accordion for the metadata block is empty when its open:

When I choose another template or "None" from the Dataset Template dropdown menu, the new metadata block appears.

[jggautier]

After the new "Computational Workflow" metadata block is added (#8639), those who may want to include that metadata block's fields in dataset metadata templates that were already created may not be able to.

[jggautier]

For the Dataverse Collection in the screenshots, I created a new dataset template; copied the metadata values from the older template to the new one; saved the new template and made it the collection's default template; and deleted the older template. So now when datasets are created in the collection, the new default template, which includes the custom metadata block, is being used instead, and the custom metadata block appears with its required fields, instead of appearing empty.

Before creating a new template and copying the metadata values from the old template to the new one, I tried using the button for copying the dataset template, but the custom metadata block also was not in that copy. So I had to re-create the dataset template "manually".

So the larger issue - that when a metadata block is added, it's not available in any dataset templates created before the metadata block was added - no longer affects the collection in the screenshot. I consider re-creating the template to be a workaround.

But I still think it can be a problem, since other new metadata blocks, such as the "Computational Workflow" metadata block, won't be available in dataset templates created before the metadata block was added.