Add command to reassign feast data and update chants

[lucasmarchd01]

Adds a management command that will transfer data between feasts and update chants accordingly.

• Ensure data from old feasts are transferred to new feasts
• Update chants and sequences to use new feast IDs
• Delete old feasts after reassignment

Towards #1560, once we run the command on production we can close the issue.

[dchiller]

Looks good! My only thought would be to make the old feast, new feast parameters into command line arguments.

On the plus side, that would mean you could use this command additionally where needed without having to go through the review process of getting a change to the code merged.

On the minus side, maybe we want that kind of review for something that makes these kinds of bulk changes. Also this way we have a record of past "feast merges".

Ok, I think the way you did it was better!

[lucasmarchd01]

On the plus side, that would mean you could use this command additionally where needed without having to go through the review process of getting a change to the code merged.

On the minus side, maybe we want that kind of review for something that makes these kinds of bulk changes. Also this way we have a record of past "feast merges".

Good points! You're right, it's probably safest to have a review process for reassigning feasts. But I'll make the mapping a global variable for readability/modification in the future.