This adds configurable timeouts for the Dart VM. Due to some testing
machines running things quite slowly, this is becoming more necessary.

* [frdp] Add optional dart isolate filter.

It's now default to filter out non-flutter isolates when searching
across Dart VM's.  This is due to a possible issue wherein an Isolate
for testing might have the same name as the flutter Isolate.

In addition, logging messages have been added in dart_vm.dart for
debugging.

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test

It was causing problems rolling Flutter into Fuchsia

* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

This reverts commit cc1cf13e.

Unbreaks flutter-build

This prevents the error:

`type 'List<dynamic>' is not a subtype of type 'List<Map<String, dynamic>>' `

The test added fails when dart_vm.dart is reverted to `master`, and succeeds in
its current state.  This issue was run into while connecting to the
Dart VM.

* Bump mockito to 3.0.0-beta

* Few fixes

* fix test

* Bump image

* Fix

* New packages update

* With matcher pinned

* No more typed

The new matcher package deprecates isInstanceOf which seems eggregious.

* Revert "Revert "Move mockito to 3.0.0-alpha. (#15949)" (#15979)"

This reverts commit e59651f9.

* More thenReturn to thenAnswer when mocking Futures

* Revert "More thenReturn to thenAnswer when mocking Futures"

This reverts commit 194d2cf41754ad171efd6bb5898cf73bce5a75ab as we are reverting engine roll.

* Revert "Revert "More thenReturn to thenAnswer when mocking Futures""

This reverts commit 52c9e96b304b220f66d78a252fccea0c8e0ef24c.

* Add dependency override

* Fix issue

This reverts commit a7e62258 as there are failing tests.

* Move mockito to 3.0.0-alpha.

This is needed so it matches mockito version used internally.

* Pick up +2 for the fixes

* Fix whenReturn in fuchsia_remote_debug_protocol

* more thenReturn becomes thenAnswer

* more thenReturn becomes thenAnswer

* more thenReturn becomes thenAnswer

Adds a package that will support connecting to and debugging devices with multiple instances of the Dart VM, and operate on multiple Isolates and Flutter Views.

Currently supports connecting to all existing Dart VMs and extracting information about all Flutter Views running across each VM.