Add ignorelist for ASAN

[alanking]

Feature

UBSAN support is being added with #390 and will include an ignorelist in order to exclude third party code from sanitation reports. ASAN also supports ignorelists, so we should add support for that in the same manner.

[MartinFlores751]

To put a bit more words, all sanitizers use the -fsanitize-ignorelist flag. If we wish to add ignores for ASAN, we would move the flag to the shared flags that are set for the sanitizers (to make things more obvious), and add them to the existing file (for HTTP API at least).

Or use separate ignore files, but that might make things a bit confusing?

Link to ignore list docs: https://releases.llvm.org/13.0.1/tools/clang/docs/SanitizerSpecialCaseList.html

[MartinFlores751]

Another thing to consider for the ignore list (suggested by @SwooshyCueb, see #369 (comment)), use src:/opt/irods-externals/* to ignore all externals.

Relevant here since it would affect all sanitizers used if not scoped.