Pull request #3195: Suppressions

Pull request #3195: Suppressions

Merge in SNORT/snort3 from ~RUCOMBS/snort3:suppressions to master

Squashed commit of the following:

commit 31b54def9246a74832e9738c959dfc0f9d0bb5c2
Author: russ <rucombs@cisco.com>
Date:   Thu Dec 2 10:14:27 2021 -0500

    build: clean up some cppcheck style issues

commit b1b17796b9f24c5666af92f2f6939da9decd5020
Author: russ <rucombs@cisco.com>
Date:   Wed Dec 1 09:45:46 2021 -0500

    build: add cppcheck suppressions for unusedFunctions

    Start migrating suppressions from an external file to source comments.
    Only functions that are actually called (and reported as covered) are
    candidates for suppression.  In this case, we have Lua FFI and STL
    overrides.