Upgrade to TypeScript 3.9.3

I was hitting a bug in 3.9.2 with the breadcrumbs CL [1] that is fixed
in 3.9.3 via this PR [2]. (I've verified locally that it is fixed).

[1]: microsoft/TypeScript#38535
[2]: microsoft/TypeScript#38577

DISABLE_THIRD_PARTY_CHECK=typescript update


Change-Id: Ia874e5936a5bbf0bf26f751ab746976f71910f25
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2218013
Commit-Queue: Jack Franklin <[email protected]>
Auto-Submit: Jack Franklin <[email protected]>
Reviewed-by: Tim van der Lippe <[email protected]>

Author: jackfranklin