Vault 20270 docker test raft wal

[hghaf099]

Addresses https://hashicorp.atlassian.net/browse/VAULT-20270

Adding tests to satisfy the following:

* raft-wal doesn’t lose data

* There is no migration procedure for individual nodes. The correct procedure is destroying existing raft-boltdb nodes and starting brand new nodes that use raft-wal (and vice-versa)

* Having a cluster of mixed nodes, some using raft-boltdb and some using raft-wal, is not a problem.

* Nodes running raft-wal can restore snapshots taken while raft-boltdb

[github-actions[bot]]

CI Results: Failures:

Test Type	Package	Test	Logs
	vault/external_tests/sealmigration	TestSealMigration_ShamirToTransit_Post14	view test results
	vault/external_tests/sealmigration	TestSealMigration_ShamirToTransit_Post14/raft	view test results
	vault/external_tests/sealmigration	TestSealMigration_TransitToShamir_Post14	view test results
	vault/external_tests/sealmigration	TestSealMigration_TransitToShamir_Post14/raft	view test results
	vault/external_tests/sealmigration	TestSealMigration_TransitToTransit	view test results
	vault/external_tests/sealmigration	TestSealMigration_TransitToTransit/raft	view test results
race	vault/external_tests/sealmigration	TestSealMigration_ShamirToTransit_Post14	view test results
race	vault/external_tests/sealmigration	TestSealMigration_ShamirToTransit_Post14/raft	view test results
race	vault/external_tests/sealmigration	TestSealMigration_TransitToShamir_Post14	view test results
race	vault/external_tests/sealmigration	TestSealMigration_TransitToShamir_Post14/raft	view test results

and 12 other tests

[github-actions[bot]]

Build Results: All builds succeeded! :white_check_mark:

[schavis]

Removing vault-education-approvers from the PR as there don't seem to be any documentation updates. But feel free to re-add if need.