Update: Mikrotik brand logo and icons + darkmode variant

[createthisnl]

Proposed change

Updated Mikrotik brand logo and icons. Also added dark mode variant.
According to Mikrotik Brand Guidelines https://mikrotik.com/logo

Type of change

• Add a new logo or icon for a new core integration
• Add a missing icon or logo for an existing core integration
• Add a new logo or icon for a custom integration (custom component)
  • I've added a link to my custom integration repository in the PR description
  • I've opened up a PR for my custom integration on the Home Assistant
    Python wheels repository
• Replace an existing icon or logo with a higher quality version
• Replace an existing icon or logo after a branding change
• Removing an icon or logo

Additional information

• This PR applies to core_integrations/mikrotik, custom_integrations/mikrotik_api and custom_integrations/mikrotik_router

Checklist

• The added/replaced image(s) are PNG
• Icon image size is 256x256px (icon.png)
• hDPI icon image size is 512x512px for ([email protected])
• Logo image size has min 128px, but max 256px, on the shortest side (logo.png)
• hDPI logo image size has min 256px, but max 512px, on the shortest side ([email protected])

[frenck]

Nice! Thanks, @createthisnl 👍

../Frenck