Allow displaying an SVG logo using svg source

[Kicu]

Problem

In current version of this library only image assets (like *.png and other raster images) can be used as a logo image within QR code. Using an SVG asset for the logo is not possible.

Solution

This PR tries to make it possible to use svgs in said logo image.

I have not found any reasonable way to do this via a single logo prop, as there is no React component that could accept either ImageSourcePropType or an SVG and handle every case correctly. Some conditional logic is required to handle the svg prop, thats why I decided to add it as a new prop, while the old logo prop will work unchanged.
That makes this new functionality backwards compatible. If you won't use new logoSVG prop - the library will work as it used to.

Done

• add (optional) logoSVG prop that accepts an svg and will render it
• add (optional) logoColor prop to set the fill property of the svg logo
• this solution handles:
  • a string svg, ex: "<svg ....>"
  • an URL pointing to an svg image, ex: https://raw.githubusercontent.com/software-mansion/react-native-svg/4b51a41a22432030a3396e847dc7d5aec5a86ae9/TestsExample/assets/ruby.svg
  • an svg React component - this is a popular format that one can get via using @svgr/webpack - which allows one to load SVGs directly using import and webpack will handle them by transforming into functional component that returns na svg
• on web we will either render the svg logo if its a component OR in case of string we use standard Image from react-native-svg
• on native ios/android we use special dedicated components from react-native-svg which will handle all these cases

Examples

ios and android

web

[luacmartins]

LGTM