new: Add support for region and type migrations; add migration_type field

[lgarber-akamai]

📝 Description

This PR adds support for running region and type ("resize") migrations on existing instances using the linode.cloud.instance module.

Additionally, this change adds the auto_disk_resize field to allow for automatically resizing implicit disks on type change operations.

Depends on linode/linode_api4-python#340

✔️ How to Test

E2E Testing:

Cross-Region Migration

NOTE: This test currently needs to be run against prod due to availability limitations. Additionally, this test is expected to fail until dev has been merged in linode/linode_api4-python#340.

make TEST_ARGS="-v instance_region_migration" test

Resize Migration

export TEST_API_URL=...
export TEST_API_CA=...
export LINODE_TOKEN=...

make TEST_ARGS="-v instance_type_change" test

Manual Testing

TODO

[ykim-akamai]

Looks good! Everything worked as expected locally