enhancement #64 : adding say text method

[FabienDanieau]

Check if the generated pb2 are ok.

Version of the tools in my env:
grpcio 1.59.2
grpcio-tools 1.59.2
protobuf 4.25.0

[glannuzel]

I guess we don't have the same version to generate the python files, as they are all modified here.

[simheo]

Closing this pull request as I fear that there will be too much conflict with develop branch.
There are two problems in this situation:

1. renaming: recently the library name has changed from reachy-sdk-api-v2 to reachy2-sdk-api. Here in the branch the former naming was used hence the pb file generated in the reachy_sdk_api_v2 folder.
2. grpc libraries versions. Because no version is specified for each of the libraries used to generate the pb files, each and every one of us has a different setup to generate the pb files. This can lead to massive git diff when doing the pull requests just like here.

I will generate the pb files for the changes you made @FabienDanieau in #68. I opened the issue #69 to specify the versions for the protobuf libraries and generate properly once and for all the pb files in a setup that we can all have on our laptops.