Refactor user and instance manager (#837)

* Refactor UserManager to use Datastore

* Rename lib.User to UserDetails also adds to/fromUserDetails

* Fix existing tests

* Add user class tests

* Add tests for finaliseUsers

* Move HostDetails to own file with tests

* Move InstanceDetails to its own file with tests

* Rename HostInfo and add tests

* Rename InstanceInfo and add tests

- Also changes the names of the host properties related to instances
- Also removes the need to specify the location of InstanceInfo

* Make json round trip test validate schema

* Add InstanceManager

* Fix lint errors

* Extra tests

* Add final test coverage

* Add one last test to InstanceManager

* Response to comments

* Use generator rather than return anonumous generator

Co-authored-by: Hornwitser <github@hornwitser.no>

* Fix lint issue with generator

---------

Co-authored-by: Hornwitser <github@hornwitser.no>

test/host.js

@@ -12,7 +12,7 @@ describe("Host testing", function() {
 	describe("discoverInstances()", function() {
 		it("should discover test instance", async function() {
 			const instancePath = path.join("test", "file", "instances");
-			const instanceInfos = await _discoverInstances(instancePath);
+			const instances = await _discoverInstances(instancePath);
 
 			const configPath = path.join(instancePath, "test", "instance.json");
 			const referenceConfig = new lib.InstanceConfig("host", {
@@ -21,7 +21,7 @@ describe("Host testing", function() {
 				"instance.name": "test",
 			}, configPath);
 
-			assert.deepEqual(instanceInfos, new Map([
+			assert.deepEqual(instances, new Map([
 				[1, {
 					config: referenceConfig,
 					path: path.join(instancePath, "test"),