chore(refactor): track grpcProcess in the model structure (#3663)

* chore(refactor): track grpcProcess in the model structure

This avoids to have to handle in two parts the data relative to the same
model. It makes it easier to track and use mutex with.

This also fixes races conditions while accessing to the model.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* chore(tests): run protogen-go before starting aio tests

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* chore(tests): install protoc in aio tests

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

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Signed-off-by: Ettore Di Giacinto <mudler@localai.io>