Remove HDFAttribIO and similar legacy classes from codebase.

[quantumsteve]

Please review the developer documentation
on the wiki of this project that contains help and requirements.

Proposed changes

Describe what this PR changes and why. If it closes an issue, link to it here
with a supported keyword.

This removes remaining uses of HDFAttribIO from the QMCPACK codebase. I also use hdf_archive::push and hdf_archive::pop instead of keeping the HDF5 group data_id open throughout the life of ObservableHelper.

This fixes #4156.

What type(s) of changes does this code introduce?

Delete the items that do not apply

• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Testing changes (e.g. new unit/integration/performance tests)

Does this introduce a breaking change?

• No

What systems has this change been tested on?

laptop, Ubuntu 20.04

Checklist

Update the following with a yes where the items apply. If you're unsure about any of them, don't hesitate to ask. This is
simply a reminder of what we are going to look for before merging your code.

• Yes. This PR is up to date with current the current state of 'develop'
• Yes. Code added or changed in the PR has been clang-formatted
• Yes/No. This PR adds tests to cover any new code, or to catch a bug that is being fixed
• Yes/No. Documentation has been added (if appropriate)

[ye-luo]

Test this please