fix: Rename directory containing proto files

[niloc132]

In order to make directory structures usable for downstream projects seeking to add new services or messages that depend on our own proto files, ensure that we name/package consistently for all languages.

This may be a breaking change for some downstream consumers, but these changes should prevent needing to make future changes or add additional build steps. Two places this may impact applications:

• The Python client proto package has been renamed from pydeephaven.proto to deephaven_core.proto. The old import will continue to work in this release, but will warn the first time it is referenced.
• The deephaven-proto-backplane-grpc.jar still contains the .proto files, but they are located in the deephaven_core/proto directory instead of at the root of the jar.

Fixes #6376

[niloc132]

Technically breaking changes in the deephaven-proto-backplane-grpc jar:

$ unzip -l proto/proto-backplane-grpc/build/libs/deephaven-proto-backplane-grpc-0.37.0-SNAPSHOT.jar

...
        0  1980-02-01 00:00   deephaven_core/
        0  1980-02-01 00:00   deephaven_core/proto/
     1467  1980-02-01 00:00   deephaven_core/proto/application.proto
     1294  1980-02-01 00:00   deephaven_core/proto/config.proto
    17768  1980-02-01 00:00   deephaven_core/proto/console.proto
    11218  1980-02-01 00:00   deephaven_core/proto/hierarchicaltable.proto
     1260  1980-02-01 00:00   deephaven_core/proto/inputtable.proto
     7082  1980-02-01 00:00   deephaven_core/proto/object.proto
     3707  1980-02-01 00:00   deephaven_core/proto/partitionedtable.proto
     9090  1980-02-01 00:00   deephaven_core/proto/session.proto
     4729  1980-02-01 00:00   deephaven_core/proto/storage.proto
    40195  1980-02-01 00:00   deephaven_core/proto/table.proto
      944  1980-02-01 00:00   deephaven_core/proto/ticket.proto
     8064  1980-02-01 00:00   META-INF/LICENSE
      527  1980-02-01 00:00   META-INF/NOTICE
---------                     -------
 11033853                     1284 files

[devinrsmith]

Couple small things, look great.

[devinrsmith]

Hmm... I see docs here, but docs/source/conf.py is not being excluded, I'm guessing b/c it has a .py extension.

[niloc132]

Apparently the exclude isn't recursive, will investigate.

[chipkent]

The directory structure doesn't contain __init__.py files, so I wonder if it is not treating it as a package and therefore not excluding. Just a wild guess.

[niloc132]

Right, we only want it to be a namespace, not a module - if we required that there be a __init__.py file, that could conflict with other wheels from contributing to it (at least without stomping on each other).

[niloc132]

Current test failure is a packaging-for-the-test issue:

======================================================================
ERROR [0.000s]: setUpClass (tests.test_barrage.BarrageTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/python/tests/test_barrage.py", line 30, in setUpClass
    cls.ensure_server_running()
  File "/python/tests/test_barrage.py", line 39, in ensure_server_running
    from pydeephaven.session import Session
  File "/opt/deephaven/venv/lib/python3.10/site-packages/pydeephaven/__init__.py", line 28, in <module>
    from .session import Session
  File "/opt/deephaven/venv/lib/python3.10/site-packages/pydeephaven/session.py", line 21, in <module>
    from pydeephaven._app_service import AppService
  File "/opt/deephaven/venv/lib/python3.10/site-packages/pydeephaven/_app_service.py", line 7, in <module>
    from deephaven_core.proto import application_pb2_grpc, application_pb2
ModuleNotFoundError: No module named 'deephaven_core'

[nbauernfeind]

LGTM