Submission version redirect is infinite loop if instance ID is encoded

[matthew-white]

For several endpoints for the logical submission, if you specify the instance ID of a submission edit, Backend will redirect to the corresponding submission version endpoint:

central-backend/lib/resources/submissions.js

Lines 360 to 375 in e9dba19

	// if we match the logical id, we stick around. otherwise we redirect.
	const getOrRedirect = (Forms, Submissions, { params, auth, originalUrl, queryOptions }) =>
	Promise.all([
	getForm(params, Forms),
	Submissions.getByIds(params.projectId, params.formId, params.instanceId, draft, queryOptions)
	])
	.then(([ form, maybeSub ]) => Promise.all([
	auth.canOrReject('submission.read', form),
	maybeSub.map(resolve).orElseGet(() =>
	Submissions.getRootForInstanceId(form.id, params.instanceId, draft)
	.then(getOrNotFound)
	.then((rootId) => redirect(originalUrl.replace(
	`/submissions/${params.instanceId}`,
	url`/submissions/${rootId}/versions/${params.instanceId}`
	))))
	]));

For example, on the QA server, there's a submission edit whose instance ID is uuid:adcaefa3-91d7-4770-a49a-1f5607d0f2f3. The instance ID of the root submission version is uuid:4b2b3e15-5675-4baf-9111-1a548cf312cd. When I request https://test.getodk.cloud/v1/projects/414/forms/children_registration/submissions/uuid:adcaefa3-91d7-4770-a49a-1f5607d0f2f3, the redirect happens as expected. However, if the : in the instance ID is encoded, the redirect doesn't happen: https://test.getodk.cloud/v1/projects/414/forms/children_registration/submissions/uuid%3Aadcaefa3-91d7-4770-a49a-1f5607d0f2f3. Instead, I get an ERR_TOO_MANY_REDIRECTS.

I think the issue is that if the instance ID is encoded in originalUrl, then originalUrl does not contain `/submissions/${params.instanceId}`, because params.instanceId is not encoded. In that case, it doesn't complete the replacement, so it ends up redirecting the user to the same originalUrl.