.github/codeql/edk2.qls: Enable CWE 457, 676, and 758 queries

The previous commits fixed issues with these queries across various
packages. Now that those are resolved, enable the queries in the
edk2 query set so regressions can be found in the future.

Enables:

1. cpp/conditionallyuninitializedvariable
   - CWE: https://cwe.mitre.org/data/definitions/457.html
   - @name Conditionally uninitialized variable
   - @description An initialization function is used to initialize a
                  local variable, but the returned status code is
                  not checked. The variable may be left in an
                  uninitialized state, and reading the variable may
                  result in undefined behavior.
   - @kind problem
   - @problem.severity warning
   - @security-severity 7.8
   - @id cpp/conditionally-uninitialized-variable
   - @tags security
     - external/cwe/cwe-457
2. cpp/pointer-overflow-check
   - CWE: https://cwe.mitre.org/data/definitions/758.html
   - @name Pointer overflow check
   - @description Adding a value to a pointer to check if it
                  overflows relies on undefined behavior and
                  may lead to memory corruption.
   - @kind problem
   - @problem.severity error
   - @security-severity 2.1
   - @precision high
   - @id cpp/pointer-overflow-check
   - @tags reliability
     - security
     - external/cwe/cwe-758
3. cpp/potential-buffer-overflow
   - CWE: https://cwe.mitre.org/data/definitions/676.html
   - @name Potential buffer overflow
   - @description Using a library function that does not check
                  buffer bounds requires the surrounding program
                  to be very carefully written to avoid buffer
                  overflows.
   - @kind problem
   - @id cpp/potential-buffer-overflow
   - @problem.severity warning
   - @security-severity 10.0
   - @tags reliability
     - security
     - external/cwe/cwe-676
   - @deprecated This query is deprecated, use
                 Potentially overrunning write
                 (`cpp/overrunning-write`) and
                 Potentially overrunning write with float to string
                 conversion
                 (`cpp/overrunning-write-with-float`) instead.

Note that cpp/potential-buffer-overflow is deprecated. This query
will be updated to the succeeding queries in the next commit. The
query is used in this commit to show that we considered and tested
the query in history.

Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael Kubacki <mikuback@linux.microsoft.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Oliver Smith-Denny <osd@smith-denny.com>

.github/codeql/edk2.qls

@@ -8,7 +8,14 @@
 
 # Enable individual queries below.
 
+- include:
+    id: cpp/conditionallyuninitializedvariable
 - include:
     id: cpp/infinite-loop-with-unsatisfiable-exit-condition
 - include:
     id: cpp/overflow-buffer
+- include:
+    id: cpp/pointer-overflow-check
+- include:
+    id: cpp/potential-buffer-overflow
+