[taped] Add additional metrics for monitoring cta-taped data transfers

Description

This MR adds the following metrics:

• cta.taped.transfer.file.size -> Counter for number of bytes transferred in the given direction using the given medium
• cta.taped.transfer.file.count -> Counter for number of files transferred in the given direction using the given medium
• cta.taped.transfer.active -> UpDownCounter for number of threads actively transferring files
• cta.taped.buffer.usage -> Gauge for the number of bytes in use by the memory buffer in cta-taped
• cta.taped.buffer.limit -> Gauge for the number of bytes allocated by the memory buffer in cta-taped

Checklist

• Documentation reflects the changes made.
• Merge Request title is clear, concise, and suitable as a changelog entry. See our contributing docs

References

Closes #1323 (closed)