Use Common XML serializer to manage xml documents

[mpostol]

Describe the bug

In many places XmlSerializer is used. The common implementation is located in the UAOOI.Common.Infrastructure

Expected behavior

Refer to the existing implementation of the serialize/deserialize functionality

Tasks list

• [x] review the code to find XmlSerializer
• [x] replace it with appropriate reference
• [x] improve sterilization to avoid many definitions of the namespace

[mpostol]

blocker and contributes to mpostol/UA-Nodeset#7