Extend Project web API

[cubap]

Improve the GET /project/{id} endpoint to return the type of thing expected. Actual connections to the database can be mocked for now.

See #2 for expectations as well as #26 for docs about possible parameters in the request to handle.

Write the failing tests first, then build to suit.

For now, a Project will look like this:

{ 
  "id"          : "#ProjectId",
  "@context"    : "http://t-pen.org/3/context.json",
  "@type"       : "CreativeWork",
  "creator"     : "https://store.rerum.io/v1/id/hash",
  "group"       : "#GroupId",
  "layers"      : [ "#LayerId" ],
  "lastModified": "#PageId",
  "viewer"      : "https://static.t-pen.org/#ProjectId",
  "license"     : "CC-BY",
  "manifest"    : "https://example.com/manifest.json",
  "tools"       : [],
  "options"     : {}
}

This will be stored in a database that is not set up yet, but you can assume a database controller abstraction with db.getByID() and db.find({property: match}) at a minimum, the return of which will be a JSON that contains the minimum unique Project information.

This endpoint should also provide alternate returns for certain parameters:

• ?text=blob a complete blob of text of all lines concatenated
• ?text=layers an Array with each discrete layer as an entry { "name" : Layer.name, "id" : "#AnnotationCollectionId", "textContent" : "concatenated blob" }
• ?text=pages an Array of Pages, each with discrete layer as an entry { "name" : \Layer.name, Page.name`, "id" : "#AnnotationPageId", "textContent" : "concatenated blob" }`
• ?text=lines an Array of Pages, then Layers with "textContent" above as `"lines" : [ { "id" : "#AnnotationId", "textualBody" : "single annotation content" }
• ?image=thumb the URL of the default resolution of a thumbnail from the Manifest
• ?lookup=manifest (layers[], annotations[], metadata[], group) find the related document or Array of documents and return that instead, the version allowed without authentication
• ?view=json is the default, no querystring request and is redundant
• ?view=xml is a chance to get the document as an XML file
• ?view=html is a readonly viewer HTML Document presenting the project data
• ?embed=true instructs methods that would have returned a URI to expand that and dereference the full document in its place

These parameters are all mutually exclusive except embed and passing multiple or a nonsense combo ("?view=html&embed=true") is an error.

[thehabes]

Note that Linked Data principles state that the @context property should always be the first property in JSON-LD objects.

• https://www.w3.org/TR/json-ld11/#example-22-combining-external-and-local-contexts
• https://iiif.io/api/presentation/3.0/#46-linked-data-context-and-extensions

[cubap]

"@context"    : "http://t-pen.org/3/context.json",
"@type"       : "CreativeWork",

These are not needed here. Who's idea was this?