Fix QR code generating without white background

[Cormac131]

Description

Fix QR code generating without a white background. Changed to PNG as when testing HA theme was overwriting the SVG elements background colour.

• Change QR code generation to PNG
• Import pypng as a dependency

After changes:

Light:

Dark:

Fixes # 112

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Local Testing

Diagnostic File

None needed, visual bug

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[Cormac131]

@shihuimiao @zlinoliver can you take a look at this PR?

[Sir-Udo]

Hi,
for a few weeks now, every time I restart HA, I've been asked to re-authenticate myself in Smartlife. Can this be fixed?
I heard it was similar at TUYA, they probably fixed it at Tuya. Thanks Udo