Agsconfig

Fixes
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- Improved service access information and description processing

New Features
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- Added the ability to get XML Metadata out of an SD Draft. This functionality is likely to change over time, with perhaps expanded support for parsing it, interacting with it via AGS JSON, and setting it (which may work now, but isn't tested).

Fixes
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- Improved ArcGIS REST Admin JSON templating/creation

Fixes
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- Fixed issue with `summary` being edited on the server

Fixes
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- Fixed issue with `access_information` on SD Drafts from ArcGIS Pro

New Features
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- Added `is_cached` property for cached services