Parameterize migration status check wait time

[AnthonyAtherton]

Description

Depending on the overall duration, including queue time for a migration, the account handling the migrations using GEI will hit the graphql API limit.

There is a hardcoded 10 second wait time for checking the status of the running migration. Adding a "command" to set the time between calls checking migration status or statically increasing the time waiting between calls to something like 5 minutes would greatly improve the ability to parallelize migrations since it would allow for more migrations from the same account.

https://github.com/github/gh-gei/blob/main/src/Octoshift/Commands/WaitForMigration/WaitForMigrationCommandHandler.cs#L12

[dylan-smith]

There should be no need to run multiple migration scripts in parallel. Create a script (or use the generate-script command to do it for you) and use the --queue-only flag to queue them all up, and let the GEI backend handle parallelizing them for you.