Removed subject-checksums input from attest action.

Removed the step for generating sha256 hash from CI workflow.

Add unicode red "x" to signify a blocked call or station

and place it in a separate member function file in JS8_Mainwindow
- Add UI hooks for Auto Reply confirmation back into the function
- Remove redundant member function declarations from mainwindow.cpp that
left over after moving the function to separate files, leaving only the
function call sites
- Move source file comments to the mainwindow header