Adding job completion message to convertpw4qmcpack

[kayahans]

Proposed changes

Currently, convertpw4qmcpack gives no confirmation to the user if the conversion is successfully complete or not. I know the plan is to incorporate this code into pw2qmcpack, but for the short term this can be a reasonable solution.

Does this introduce a breaking change?

• No

What systems has this change been tested on?

• ORNL-Baseline

Checklist

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

[prckent]

Useful improvement. I changed message to be the same style as the QMCPACK completion message (qmcapp.cpp:229). I also prefer we avoid use the term "job" since this is associated with queuing systems.

[prckent]

Test this please