Update VISSR version

[slawr]

CDSP last updated the VISSR version it uses several months ago, whilst the upstream project has continued to evolve. We should look to update to the latest version.

High level task outline:

• Decide VISSR version and create summary of likely code impact (required changes)
• Update submodule and version used in docker
• Sanity test VISSR operation, including with IoTDB
• Update CDSP documentation where necessary

VISSR upstream tasks:

• Send fix for dockerfile related to protobuf dir copy

Input notes:

1. @UlfBj has provided the following helpful note about a change in behavior:

I saw the following in your text
You can query what VSS nodes the server understands by asking for the VSS path list using the URL http://localhost:8081/vsspathlist. Entering that URL in your web browser will typically give you a graphical rendering of the JSON data returned.
This is true for VISSRv2.0 (on the v2.0 branch) but not for VISSRv3.0 (on master branch) where I had to diable it due to the new multitree support (it could be restored).

Implementation notes

• VISSR version
  • VISSR continues to not have named releases so decided to take the current latest commit on master branch, which at start of work is 11617fa0478b. Eventually integrated 7447c1 (file transfer fix requested by @UlfBj)
• Initial VISSR code investigation summary
  • Check if the support for Apache IoTDB in VISSR needed any changes in update from VISSR v2 to v3
    • Storage backend API for DB get/set unchanged so in theory 'its ok'. Confirm with sanity testing when updated in Playground
  • VISSR Readme build instructions do not suggest any changes needed for docker build
• Integration
  • Docker build
    • docker build fails on https://github.com/COVESA/vissr/blob/96fb4f805a42b365575c7d50518eb2057c7a1618/Dockerfile.rlserver#L30. Copying directory protobuf in build stage when it no longer exists. Removed locally for now. Needs fix upstream.
    • gRPCClient build failures (reported in VISSR issue Undefined functions in vissv2server/grpcMgr/testprocess/gRPCClient.go leads to build errors vissr#70 and fixed):

52.78 server/vissv2server/grpcMgr/testprocess/gRPCClient.go:17:21: undefined: utils.Compression
52.78 server/vissv2server/grpcMgr/testprocess/gRPCClient.go:49:15: undefined: pb.NewVISSv2Client
52.78 server/vissv2server/grpcMgr/testprocess/gRPCClient.go:54:58: too many arguments in call to utils.SubscribeRequestJsonToPb
52.78 	have (string, unknown type)
52.78 	want (string)

• Docker runtime
  • Startup fails due to missing viss.him. Investigation revealed other new runtime files required.
• Docker issues resolved upstream in PR Dockerfile.rlserver: update vissv2server target for VISSR v3 vissr#79. See PR for details.
• Documentation
  • Added VISS/VISSR examples to online doc examples page
  • Updated Docker readme.md to reflect VISSR v3 changes.

[slawr]

@UlfBj has helpfully pointed out that VISSR now has a hello-world example here https://covesa.github.io/vissr/build-system/hello-world/. We should point to it in CDSP examples list in the documentation site. I mention it here as we should first check whether it needs VISSRv3, i.e. whether we need to do this update first.

[slawr]

Upstream VISSR work was clarified in VISS/VISSR Slack channel with maintainers. Changes have been merged upstream and integrated downstream in CDSP. CDSP now uses VISSR latest commit. CDSP doc also updated.

All tasks complete. Changing WIP status from WIP to ready for review/merge.