Revert "Delete root header file typedefs.h. Part 2."

This reverts commit 4e307f2d880152bbf2a102c8279ebaad7b0aabd7.

Reason for revert: Breaks chromium, file was included in third_party/libjingle_xmpp/xmpp/xmpplogintask_unittest.cc

Original change's description:
> Delete root header file typedefs.h. Part 2.
> 
> This is a followup to
> https://webrtc-review.googlesource.com/c/src/+/90249, which deleted
> all uses of the typedefs.h throughout the source tree, but didn't
> actually delete the file itself.
> 
> This cl deletes the file, and also deletes mention of it in the top-level
> DEPS file.
> 
> TBR: kwiberg@webrtc.org
> Bug: webrtc:6854
> Change-Id: I90bb72961ff7e9f3ac8b7123cfc1177143d77a20
> Reviewed-on: https://webrtc-review.googlesource.com/90410
> Reviewed-by: Niels Moller <nisse@webrtc.org>
> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
> Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
> Commit-Queue: Niels Moller <nisse@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#24149}

TBR=solenberg@webrtc.org,mbonadei@webrtc.org,kwiberg@webrtc.org,nisse@webrtc.org

Change-Id: I9c3e2099ecd5bf848827f89374fe1a0488a98823
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:6854
Reviewed-on: https://webrtc-review.googlesource.com/91420
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24150}