feat(diagnostics): Add diagnostics buckets setup

[Josh-Matsuoka]

Fixes #260

Adds the diagnostics buckets (threaddumps, heapdumps) to the CRYOSTAT_BUCKETS environment variable for cryostat storage, as well as adding the STORAGE_BUCKETS_THREAD_DUMPS_NAME and STORAGE_BUCKETS_HEAP_DUMPS_NAME environment variables to the cryostat container. Adjusts the tests accordingly.

To test:

• Spin up a crc cluster or any other test environment
• helm install --set core.discovery.kubernetes.enabled=true --set core.discovery.kubernetes.namespaces='{default}' --set core.image.repository=quay.io/jmatsuok/cryostat cryostat ./charts/cryostat/
• install a sample application that uses the cryostat agent (heap dumps require an agent connection)
• Test the diagnostics functionality, make sure that thread and heap dumps can be triggered and downloaded, etc.
• Check the environment variables for the cryostat container, make sure that the STORAGE_BUCKETS environment variables are set.
• Check the environment variables for the storage container, make sure that CRYOSTAT_BUCKETS includes threaddumps and heapdumps