feat: Add file based ResourceStore (#52)

* feat: Add file resource store

* test: Write some tests for FileResourceStore

* fix: Reformat code and fix various small things from reviews

* fix: Change constants to just be the corresponding URL

* fix: Remove extra unnecessary wrap in a Promise

* fix: Write some more tests and fix related bugs

* fix: Use old way to import fs promises to support older Node versions

* refactor: Refactor code and tests

* refactor: Refactor and better document code

* fix: Change comparison with undefined by typeof check

* fix: Invert typeof check

package.json

@@ -32,16 +32,20 @@
     "@types/async-lock": "^1.1.2",
     "@types/cors": "^2.8.6",
     "@types/express": "^4.17.6",
+    "@types/mime-types": "^2.1.0",
     "@types/n3": "^1.4.0",
     "@types/node": "^14.0.1",
     "@types/rdf-js": "^3.0.0",
+    "@types/uuid": "^8.3.0",
     "@types/yargs": "^15.0.5",
     "async-lock": "^1.2.4",
     "cors": "^2.8.5",
     "express": "^4.17.1",
+    "mime-types": "^2.1.27",
     "n3": "^1.4.0",
     "rdf-terms": "^1.5.1",
     "sparqlalgebrajs": "^2.3.1",
+    "uuid": "^8.3.0",
     "yargs": "^15.4.1"
   },
   "devDependencies": {