Add e2etest for breakpoints in sources panel
Add e2etest for breakpoints in sources panel

The test will navigate through various part of the UI and open a file in
the sources panel. It will add a breakpoint by clicking on the
respective element in CodeMirror and verify that the top call-frame is
correct and has the correct url.

This replaces
https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/web_tests/http/tests/devtools/startup/sources/debugger/script-formatter-breakpoints-1.js;drc=ee7ea7dcf43928ef64337d8857205fa4bb4b4c5f?originalUrl=https:%2F%2Fcs.chromium.org%2F
as an e2etest.

Bug: 1044632
Change-Id: I0de893dc679c723773e437c598d422def162526b
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2047194
Commit-Queue: Tim van der Lippe <dba8716ee7f8d16236046f74d2167cb94410f6ed@chromium.org>
Reviewed-by: Simon Zünd <38944668e9e2ca98ccd0275b53370f90fa55c113@chromium.org>
Reviewed-by: Jack Franklin <993fcadce4d04090da2fefd557a0995e7966c8d5@chromium.org>
Reviewed-by: Paul Lewis <8915f5d5c39a08c5a3e8a8d7314756e4580816f9@chromium.org>

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