Add check for globals

We don't follow this cpp core guidelines rule well.  This is something
that we should aspire to cleaning up in the future, but for the moment,
lets turn the rule on in clang-tidy to stop the bleeding, add ignores
for the things that we know need some better abstractions, and work on
these over time.

Most of this commit is just adding NOLINTNEXTLINE exceptions for all of
our globals.  There was one case in the sensor code where clang
correctly noted that those globals weren't actually const, which got
missed because of the use of auto.

Tested: CI should be good enough for this.  Passes clang-tidy.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Ieda08fee69a3b209d4b3e9771809a6c41524f066
diff --git a/include/hostname_monitor.hpp b/include/hostname_monitor.hpp
index 3fb42e4..cb84ad6 100644
--- a/include/hostname_monitor.hpp
+++ b/include/hostname_monitor.hpp
@@ -11,6 +11,7 @@
 {
 namespace hostname_monitor
 {
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 static std::unique_ptr<sdbusplus::bus::match_t> hostnameSignalMonitor;
 
 inline void installCertificate(const std::filesystem::path& certPath)