Investigate possible concurrency issue in gRPC daemon during `Init`

[cmaglie]

trafficstars

Describe the problem

Following this report:

https://github.com/arduino/arduino-ide/issues/681#issuecomment-1177553584

it seems possible to have concurrent reads and writes in the arduino-cli core instances, in particular when the Init call is ongoing and another concurrent call happens (in the example above a BoardSearch has been executed together with the Init).

To reproduce

I didn't try to reproduce it yet, but I think this is a signal of a potential problem that must be solved.

Expected behavior

The CLI must not crash

Arduino CLI version

nightly

Operating system

N/A

Operating system version

Additional context

No response

Issue checklist

• [X] I searched for previous reports in the issue tracker
• [X] I verified the problem still occurs when using the nightly build
• [X] My report contains all necessary details