.github: Add initial CodeQL config and workflow files

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=4115

Adds initial support for enabling CodeQL Code Scanning in this
repository per the RFC:

  https://github.com/tianocore/edk2/discussions/3258

Adds the following new files:
  - .github/workflows/codql-analysis.yml - The main GitHub workflow
    file used to setup CodeQL in the repo.
  - .github/codeql/codeql-config.yml - The main CodeQL configuration
    file used to customize the queries and other resources the repo
    is using for CodeQL.
  - edk2.qls - A query set of queries to run for CodeQL.

Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>

.github/codeql/edk2.qls

@@ -0,0 +1,12 @@
+---
+- description: EDK2 (C++) queries
+
+# Bring in all queries from the official cpp-queries suite so individual queries can be explicitly enabled.
+
+- queries: '.'
+  from: codeql/cpp-queries
+
+# Enable individual queries below.
+
+- include:
+    id: cpp/conditionallyuninitializedvariable