Create tar.gz of legacy library with some un-migratable blocks

[kdmccormick]

Using OLX, create a legacy library .tar.gz that includes:

1. An unsupported container type: itembank (aka Problem Bank)
2. Another unsupported container type: split_test (aka Content Experiment) nvm, this is redundant with (1)
3. A block which isn't installed, e.g. my_fake_block

   <my_fake_block url_name="fake">
        This XBlock type isn't installed anywhere, because I just invented it!
   </my_fake_block>

4. A block which is broken... but not in a way that should prevent its migration. e.g., an advanced problem with malformed CAPA.
5. As a control, a non-broken builtin block, like problem
6. As a control, a non-broken external block, like drag-and-drop-v2
7. As a control, a non-broken external advanced block, like edx-sga

Name the blocks so that it's obvious to the testers what the expected behavior of each one is.

[kdmccormick]

OK here's a legacy library to acid-test the migration with: migration-test-lib.tar.gz

It includes:

• A well-formed basic problem
• A well-formed advanced multi-part problem
• A malformed problem (should import OK, but show an error while rendering)
• An edx-sga block (should import OK)
• A drag-and-drop-v2 block (should import OK)
• A ProblemBank (should import as Unsupported)
• An unrecognized block of type my_fake_block (should import as unknown)

Unfortunately, my currrent testing is showing that none of the blocks import correctly, including the well-formed ones.
Note sure if this an issue with my local env or if it's reproducible elsewhere. Will follow up tomorrow if I have time, but feel free to give it a go and let me know what you find.