Promote MSSQLVirtualNetworkRule and MSSQLDatabase to v1alpha2

[ytsarev]

Description of your changes

Promote MSSQLVirtualNetworkRule and MSSQLDatabase to v1alpha2

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

k get -f ./examples/sql/mssqlvirtualnetworkrule.yaml
NAME                                                          READY   SYNCED   EXTERNAL-NAME   AGE
mssqlvirtualnetworkrule.sql.azure.jet.crossplane.io/example   True    True     example         3h25m

NAME                                                   READY   SYNCED   EXTERNAL-NAME    AGE
resourcegroup.azure.jet.crossplane.io/example-sql-rg   True    True     example-sql-rg   3h43m

NAME                                                        READY   SYNCED   EXTERNAL-NAME   AGE
virtualnetwork.network.azure.jet.crossplane.io/example-vn   True    True     example-vn      3h43m

NAME                                                    READY   SYNCED   EXTERNAL-NAME    AGE
subnet.network.azure.jet.crossplane.io/example-subnet   True    True     example-subnet   3h43m

NAME                                                           READY   SYNCED   EXTERNAL-NAME          AGE
mssqlserver.sql.azure.jet.crossplane.io/mssql-server-example   True    True     mssql-server-example   3h25m

NAME                    TYPE     DATA   AGE
secret/mssql-password   Opaque   1      3h43m

k get -f examples/sql/mssqldatabase.yaml
NAME      READY   SYNCED   EXTERNAL-NAME   AGE
example   True    True     example         6m24s

[ulucinar]

Thank you @ytsarev, lgtm.