* cherry-pick 13a51d32 (V8 History cleanup import/export)
Support import/export for doc type history cleanup policy (#11660)
* Support import/export for doc type history cleanup policy
* Support unset/null history cleanup value
* Resolve issue when api endpoints called without cleanup policy.
noop isn't good enough as map fails for response.
* null conditional vs null coalesce assignment
* Don't overwrite existing policy if omitted in import XML
* Update history cleanup warning and translations
* Change history cleanup alert to infomational styling
* Remove margin around history cleanup config
Co-authored-by: Ronald Barendse <ronald@barend.se>
# Conflicts:
# src/Umbraco.Core/Models/IContentType.cs
# src/Umbraco.Core/Packaging/PackageDataInstallation.cs
# src/Umbraco.Infrastructure/Persistence/Repositories/Implement/ContentTypeRepository.cs
# src/Umbraco.Infrastructure/Services/Implement/EntityXmlSerializer.cs
# src/Umbraco.Tests/Packaging/PackageDataInstallationTests.cs
# src/Umbraco.Tests/Services/Importing/ImportResources.Designer.cs
# src/Umbraco.Tests/Umbraco.Tests.csproj
# src/Umbraco.Web.UI/umbraco/config/lang/en.xml
# src/Umbraco.Web.UI/umbraco/config/lang/en_us.xml
# src/Umbraco.Web/Models/Mapping/ContentTypeMapDefinition.cs
# tests/Umbraco.Tests.Integration/Umbraco.Infrastructure/Services/Importing/ImportResources.resx
# tests/Umbraco.Tests.UnitTests/Umbraco.Core/Services/Importing/SingleDocType-WithCleanupPolicy.xml
* Remove namespace aliases
* Update IContentTypeWithHistoryCleanup documentation
Co-authored-by: Ronald Barendse <ronald@barend.se>
fce97314bd