Language Resource Files unescaping "&"

Description

The issue is due to the ampersands being unescaped which results in an invalid entity for the XML. For example in DNN 9.1.1 if one wants to use   in a resource file, one would need to go   which stores without errors; however, in 9.2 Due to the change to use HTML Entities (one of the latest PR for this feature), it ends up unescaping the ampersand which results in   and either the files doesn’t save or it breaks.

Steps to reproduce

1. Go to Settings > Site Settings > Languages, and the resource files for one of the languages (en-US)
2. From the file drop-down select the GlobalResources file, see screenshot.
3. Make a small value change and attempt to save the file.

Current result

The file will not save and you will receive a 500

Expected result

The file should save the changes without issues.

Affected version

• 9.2
• 9.1.1
• 9.1
• 9.0

[tpluscode]

I think the actual issue here is using InnerXml. I think that instead we should use InnerText or a CDATA node to have the XML library ensure values get properly escaped.

See this SO question for reference: https://stackoverflow.com/questions/4679543/how-to-write-cdata-in-xml

cc @Mohtshum

[tpluscode]

Done @bdukes