Add Batyrev's construction of toric varieties to toric library

[local-ring]

This is implementation of Batyrev's paper in 1991 and 1999 on construction of toric varieties of Picard number 3 and toric Fano 3-fold/4-fold.

Under construction, not ready for review..

Part of #40269

cc: @tscrim

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.

⌛ Dependencies

[github-actions]

Documentation preview for this PR (built with commit cead6d5; changes) is ready! 🎉
This preview will update shortly after each push to this PR.

[fchapoton]

You need to add the new file to the meson build system, probably to src/sage/schemes/toric/meson.build

[fchapoton]

I have done it for you. Beware to pull the branch before doing further work.

[fchapoton]

you need to fix the linter (see Lint in the checks) and also

/home/runner/work/sage/sage/src/sage/schemes/toric/batyrev.py:7:8 - error: "sys" is imported more than once (reportDuplicateImport)
35380
Error: "sys" is imported more than once (reportDuplicateImport)