Publishing SQL Core library in nuget (#2173)

* Set up CI with Azure Pipelines

[skip ci]

* Update publishSqlCoreProject.yml for Azure Pipelines

* Update publishSqlCoreProject.yml for Azure Pipelines

* Update publishSqlCoreProject.yml for Azure Pipelines

* Update publishSqlCoreProject.yml for Azure Pipelines

* Update publishSqlCoreProject.yml for Azure Pipelines

* Updating json rpc target framework

* Fixing packages to pack

* fixing pattern

* Fixing project pattern

* adding versioning schema

* fixing versioning scheme

* fixing nuget package name

* adding name

* removing var

* Fixing stuff

* Fixing stuff

* Fixing stuff

* Fixing build name

* removing build name

* fixing name

* fixing stuff

* fix pattern

* Fixing stuff

* Fixing feed

* Fix stuff

* Fixing feed

* fixing proj name

* Fixing stuff

* Fixing netframework version

* Fixing target framework

* Adding target framework to dependency

* Fixing frameworks

* adding net7.0

* adding flag

* Fixing target frameworks and making code compatible with lang version

* fixed flag

* Fixing assembly name

* Adding hosting in nuget package

* Fixing tests

* Moving steps to its main pipeline

* only releasing when release is true

* Fixing build scripts

* Adding version to csproj for packaging

* adding version

* Fix dirs

* Adding version number to right prop group

* Adding necessary dis

* Fixing build number

* fixing datatype

* Using different var

* Removing unused yml

* Adding back nullables to hosting

* Adding back more nullables

* adding back more nullables

* moving some props to dir level

* Fixing tests

* Removing dup properties

* Supporting different target frameworks in hosting

* Removing additional setting in csproj

* signing sql core dll in publish

* Fixing version setting

* Adding to build

* Added signing and packaging flag

* Fixing file pattern

build.json

@@ -24,10 +24,6 @@
   "Frameworks": [
     "net7.0"
   ],
-  "FxFrameworks":[
-    "net472",
-    "net7.0"
-  ],
   "MainProjects": [
     "Microsoft.SqlTools.Credentials",
     "Microsoft.SqlTools.ResourceProvider",
@@ -37,7 +33,20 @@
     "Microsoft.SqlTools.Migration"
   ],
   "FxBuildProjects": [
-    "Microsoft.SqlTools.ManagedBatchParser"
+    {
+      "Name": "Microsoft.SqlTools.ManagedBatchParser",
+      "Frameworks": [
+        "net472",
+        "net7.0"
+      ]
+    },
+    {
+      "Name": "Microsoft.SqlTools.SqlCore",
+      "Frameworks": [
+        "netstandard2.0"
+      ],
+      "SkipPack": "true"
+    }
   ],
   "PackageProjects": [
     "Microsoft.SqlTools.Hosting"