Fix clearing of the selection view

Add fallback sorting to SamplingReportDataView

SamplingReportDataView used to use stable_sort. stable_sort's outcome
depends on the previous state of the container. Since recent changes
trigger a reconstruction of SamplingReportDataView stable_sort
preserving behaviour doesn't work anymore since the container's previous
state is not preserved. That lead's to reorderings observed by the user.

This can be avoided by establishing a total ordering. In this commit I
use the function address as a unique and totally ordered field.

Test: Manual UI test
Bug: http://b/167541131

check selected functions for nullptr when start a capture

add error message on load old capture and warning on save

Replace vector by deque and process messages in order

Clean up, remove unused serialization

Remove websocket related code from codebase.

Moved QtPropertyBrowser into third_party/