Create a 'render-method-parser' library

[dmitrizagidulin]

(Relevant to #519 and #518) Create a separate repo and library to process the renderMethod property of a VC.

Initially:

• If the renderMethod value is an object, just use that. If it's an array, use the first object in the array. (We'll add processing for multiple renderMethod values later.)
• Only support the SvgRenderingTemplate2023 type to start with.
• Only support linking to a template. Meaning, fetch the contents of the URL contained in the id field.
• Return a { template: { contents, mediaType } } object. contents contains the fetched contents from id (so, the SVG template), and mediaType will be text/x-handlebars to denote that Handlebars processing is needed.

Later (separate issues/PRs):

• Perform verification of the digestSRI or digestMultibase fields, throw error if digest does not match.
• Support embedded templates (as opposed to linked in the id)

[dmitrizagidulin]

I'll create the initial blank repo & README.