Define a new mechanism for loading ESDL script configurations

• Support script configurations used by components other than the ESDL service, such as log agents.
• Allow the `Scripts` element to be defined using child elements.
• Allow `CustomRequestTransform` and `Transforms` elements to be defined using encoded XML text. The list of elements allowed to embed XML text should be extensible to include, at a minimum, all transform elements.
• Allow property tree reordering, used to "fix" script operation order, to reorder regardless of namespace prefix in use.
• Parse embedded XML text in elements within documents being parsed. Parsing an XML document that contains, but is not rooted by, `Scripts` must handle the `Scripts` element content as encoded text or child elements.
• Allow elements to refer to externally defined markup as an alternative to encoded XML text. This anticipates the presence and use of a resource bundle, but could also be used to load XML files.

To be clear, the intent of this issue is to define a mechanism. Integration into existing or new code is separate.