SecurityPkg: SecureBootVariableLib: Added unit tests

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3911

This change added unit test and enabled it from pipeline for the updated
SecureBootVariableLib.

The unit test covers all implemented interfaces and certain corner cases.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Min Xu <min.m.xu@intel.com>

Signed-off-by: Kun Qin <kun.qin@microsoft.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Acked-by: Michael Kubacki <michael.kubacki@microsoft.com>

SecurityPkg/SecurityPkg.ci.yaml

@@ -15,6 +15,7 @@
         ##     "<ErrorID>", "<KeyWord>"
         ## ]
         "ExceptionList": [
+            "8005", "gRT",
         ],
         ## Both file path and directory path are accepted.
         "IgnoreFiles": [
@@ -26,6 +27,10 @@
     "CompilerPlugin": {
         "DscPath": "SecurityPkg.dsc"
     },
+    ## options defined .pytool/Plugin/HostUnitTestCompilerPlugin
+    "HostUnitTestCompilerPlugin": {
+        "DscPath": "Test/SecurityPkgHostTest.dsc"
+    },
     "CharEncodingCheck": {
         "IgnoreFiles": []
     },
@@ -33,6 +38,7 @@
         "AcceptableDependencies": [
             "MdePkg/MdePkg.dec",
             "MdeModulePkg/MdeModulePkg.dec",
+            "UnitTestFrameworkPkg/UnitTestFrameworkPkg.dec",
             "SecurityPkg/SecurityPkg.dec",
             "StandaloneMmPkg/StandaloneMmPkg.dec",
             "CryptoPkg/CryptoPkg.dec"
@@ -47,6 +53,11 @@
         "DscPath": "SecurityPkg.dsc",
         "IgnoreInf": []
     },
+    ## options defined .pytool/Plugin/HostUnitTestDscCompleteCheck
+    "HostUnitTestDscCompleteCheck": {
+        "IgnoreInf": [""],
+        "DscPath": "Test/SecurityPkgHostTest.dsc"
+    },
     "GuidCheck": {
         "IgnoreGuidName": [],
         "IgnoreGuidValue": ["00000000-0000-0000-0000-000000000000"],