fix(browser): Strip webpack wrapping from stack frames

[timfish]

Fixes #5459

I did try and solve this via the Chrome regex but found that the 2nd line ((error: https://s1.sentry-cdn.com/_static/dist/sentry/chunks/app_bootstrap_initializeLocale_tsx.abcdefg.js)) was picked up by the gecko parser. This change just strips the (error: *) wrapper from all lines before parsing proper. Line 2 is still parsed by the gecko parser but the resulting frame seems sensible even if it doesn't contain much useful info.

The following stack string:

ChunkLoadError: Loading chunk app_bootstrap_initializeLocale_tsx failed.
      (error: https://s1.sentry-cdn.com/_static/dist/sentry/chunks/app_bootstrap_initializeLocale_tsx.abcdefg.js)
        at (error: (/_static/dist/sentry/chunks/app_bootstrap_initializeLocale_tsx.abcdefg.js))
        at key(webpack/runtime/jsonp chunk loading:27:18)
        at ? (webpack/runtime/ensure chunk:6:25)
        at Array.reduce(<anonymous>)

Now results in the following frames:

        [ 
          { 
            filename: '<anonymous>', 
            function: 'Array.reduce', 
            in_app: true 
          },
          {
            filename: 'webpack/runtime/ensure chunk',
            function: '?',
            in_app: true,
            lineno: 6,
            colno: 25,
          },
          {
            filename: 'webpack/runtime/jsonp chunk loading',
            function: 'key',
            in_app: true,
            lineno: 27,
            colno: 18,
          },
          {
            filename: '/_static/dist/sentry/chunks/app_bootstrap_initializeLocale_tsx.abcdefg.js',
            function: '?',
            in_app: true,
          },
          {
            filename: 'https://s1.sentry-cdn.com/_static/dist/sentry/chunks/app_bootstrap_initializeLocale_tsx.abcdefg.js',
            function: '?',
            in_app: true,
          },
        ]