QR code generation service

[johanstokking]

Summary

QR code generation service

Why do we need this?

To generate QR codes in one place instead of moving the responsibility to the clients.

See #1407 (comment)

What is already there? What do you see now?

#1392 is introducing an offline QR code generation in CLI. This is offline, but imports QR code formats and rendering in the CLI, which may run out of sync with the server version.

We have a pkg/qrcode with the necessary plumbing

What is missing? What do you want to see?

First class service for QR code generation and potentially parsing

It returns a list of formats for entities (i.e. EndDevice and Gateway), the required field mask and has an rpc for generating the QR code. It should be able to render it (png in requested size), return a bitmap ([][]bool) and/or text value.

How do you propose to implement this?

First class component, new gRPC service, start with EndDevice and generation of QR codes, but allow for Gateway and parsing QR codes too

Can you do this yourself and submit a Pull Request?

Yes

[johanstokking]

Blocking #1407

[johanstokking]

Blocking #1392

[johanstokking]

Blocking #1209