fix(xml): extract tags map to separate entry point for mobile & web

[joshuayoes]

Summary

What issues does the pull request solve? Please tag them so that they will get automatically closed once the PR is merged

When utilizing with react-native-web: SvgXml and SvgUri are not exported in the src/ReactNativeSVG.web.ts extension. The logic for SvgXml and SvgUri do not have native dependencies, so they are safe to consume on web.

Issues:

• 'SvgXml' for web #1279
• SvgUri example as given in README.md crashes in Expo Web  #1742

What is the feature? (if applicable)

Add SvgXml and SvgUri as consumable exports for react-native-web

How did you implement the solution?

Extract tags to shapes map into separate tags.tsx file, where native shape elements and web shape elements can be provided to their respective envs.

What areas of the library does it impact?

src directory

Test Plan

Demonstrate the code is solid. Example: The exact commands you ran and their output, screenshots / videos if the pull request changes UI.

What's required for testing (prerequisites)?

n/a

What are the steps to reproduce (after prerequisites)?

n/a

Compatibility

OS	Implemented
iOS	✅
Android	✅

Checklist

• I have tested this on a device and a simulator
• I added documentation in README.md
• I updated the typed files (typescript)
• I added a test for the API in the __tests__ folder

[joshuayoes]

Another way I considered going about this was creating web.tsx shadows for each exported element in the src/elements directory.

This would be nice because it would allow src/ReactNativeSVG.web.ts to more closely resemble src/ReactNativeSVG.ts. But I figured it would make the PR noisier with lots of smaller file changes.

[WoLewicki]

@joshuayoes thanks for the contribution! Do you have knowledge how does it go with the discussion from #1279? Especially security concerns e.g. from #1279 (comment)?

[joshuayoes]

@joshuayoes thanks for the contribution! Do you have knowledge how does it go with the discussion from #1279? Especially security concerns e.g. from #1279 (comment)?

Thanks for your response. Taking a deeper look at those issues, I think this PR may not be a good solution for maximal security, which it seems the team has decided to prioritize.

However, it would be nice if there was a clearer error when trying to import these on the web. Perhaps there could be a web export that just throws an error with a link to the PRs?

[WoLewicki]

Yeah, it seems like a good solution. Maybe even better if there was a link to the #1279 and a note that if you want to use it, then there could be a link to the PRs. Would you mind opening such a PR?