feat: Add ability to import and export user schedules

[WillieCubed]

Problem Description

There currently is no way to get a machine-readable representation of user schedule data.

For the sake of usability and as a first step towards saving data to user accounts, Comet Planning should have the ability to import and export all schedules to a single file. Having this functionality would make testing data operations more robust.

Proposed Problem Solution

Using the data types defined in #3, Comet Planning will be able to export all schedule data to a single JSON file. Functions related to this functionality will be found primarily in the src/lib/transfer.js directory. On the schedule planner page found at /schedules/:id, there will be a button that reduces all data for the currently open schedule from the Redux data store to a JSON file titled schedule_{id}.json where id is the generated unique ID for the schedule.

Alternative Solutions

Eventually, in addition to saving schedule data a user document in the database, we will be able to convert schedules into a variety of forms, perhaps to a PDF or a spreadsheet format.

Additional Context

• Database types document

[WillieCubed]

@medhaaiyah When you have the time, would you be willing to add the UI for this?