Add a helper method for infallible API endpoints

[dtdesign]

A lot of RPC endpoints have turned out to be infallible, which means that they do not return an error under normal circumstances. Any error is the result of either an unexpected server error or a bug in the client code that makes the call thus all instances where such a request fails it should fail hard and loud.

This PR introduces a new alert dialog that is raised whenever such an unexpected error case is hit. This is strictly meant to be a fall-back case and should not be relied on as an expected behavior.

Example of the code before and after:

WCF/ts/WoltLabSuite/Core/Api/ModerationQueues/CloseReport.ts

Lines 14 to 26 in 3245fcd

	export async function closeReport(queueId: number, markAsJustified: boolean): Promise<ApiResult<[]>> {
	try {
	await prepareRequest(`${window.WSC_RPC_API_URL}core/moderation-queues/${queueId}/close`)
	.post({
	markAsJustified,
	})
	.fetchAsJson();
	} catch (e) {
	return apiResultFromError(e);
	}
	return apiResultFromValue([]);
	}

After the PR:

WCF/ts/WoltLabSuite/Core/Api/ModerationQueues/CloseReport.ts

Lines 14 to 22 in dccb595

	export async function closeReport(queueId: number, markAsJustified: boolean): Promise<[]> {
	return fromInfallibleApiRequest(() => {
	return prepareRequest(`${window.WSC_RPC_API_URL}core/moderation-queues/${queueId}/close`)
	.post({
	markAsJustified,
	})
	.fetchAsJson();
	});
	}