Allow validation of a cloning strategy

Right now, you can export a cloning strategy, and load it again. However, you could make changes to the sequence by editing the json file you originally exported, and re-load it again in the page, and the tree would be displayed without warnings.

There should be an optional way (not every time you load data) to validate that starting from the oldest ancestors, and following the steps written in the json, the produced sequences exactly match the ones originally exported. This could require a single api entry point that validates the whole thing, or subsequent requests. Probably several calls is better.

This would also confirm that the information we keep in the json file is sufficient to generate a deterministic tree, and could be used in tests.

For cloning strategies including sequence file submissions by the user, this would require exporting files submitted by the user when exporting the data.

Start by tracing the page's JSON export and reload flow, then identify the API entry point or sequence of requests involved in generating the tree. Define validation around reproducing the exported sequences from the oldest ancestors and document how user-submitted sequence files from issue #12 affect the scope; done means altered JSON is detected and valid exports can be checked in tests.