Update KaTeX to 0.10.0

What does this MR do?

Update KaTeX to 0.10.0.

Are there points in the code the reviewer needs to double check?

I guess you might want to wait for a non-beta version, but this beta has proved stable (relatively few commits since its release), and KaTeX doesn't do releases very often. Now updating to nonbeta version, 0.10.0. (I am one of the KaTeX contributors.)

I'm not a yarn expert but I think I did yarn upgrade katex@^0.10.0 correctly.

It might be worth checking out the new strict and maxExpand settings, but I believe the defaults should be fine.

I added support for KaTeX's \def/\newcommand macro definitions across multiple math objects, simply by passing a common macros object between these calls. I'm not familiar with your testing harness, or even your build process, so I haven't done any tests. Pointers appreciated.

Why was this MR needed?

I noticed that the KaTeX dependency was back at 0.8.3 because of a KaTeX issue raised by a Gitlab.com user: https://github.com/Khan/KaTeX/issues/1460

KaTeX has had a lot of active development since 0.8.3. See full release notes. Some highlights include better Unicode support, user-level macro support, and line breaking (both automatic and manual).

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Conform by the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • Has been reviewed by a Database specialist
• Conform by the merge request performance guides
• Conform by the style guides
• Conform by the database guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?