Header/Footer Size are Tied in GUI

[nsmryan]

The header and footer for packets are tied in the GUI for some reason, so they change together.
This feature is intended to allow separate headers and footers of any size.

This may be an imgui issue with naming or control ids.

[nsmryan]

It looks like this is due to imgui control ids, where the inputs where not given their own names.
however, even naming them doesn't seem to fix the footer issue. I'm not sure why.