assimp: Clean and document buildsystem, update to upstream 0201fc5

Added navigation mesh merging error.

- Improve the SCsub to allow unbundling and remove unnecessary code.
- Move files around to match upstream source.
- Re-sync with upstream commit 308db73d0b3c2d1870cd3e465eaa283692a4cf23
  to ensure we don't have local modifications.
- Doesn't actually build against current version 5.0.1 due to the lack
  of the new ArmaturePopulate API that Gordon authored. We'll have to
  wait for a public release with that API (5.1?) to enable unbundling.

Fix gamepad disconnection callback on macOS Catalina.

Replace IOHIDDeviceRegisterRemovalCallback with IOHIDManagerRegisterDeviceRemovalCallback to fix gamepad disconnection callback on macOS Catalina.

Removed boolean return type from majority of method in Tween

mbedtls: Update to upstream version 2.16.5

Re-architecture of the Godot Android plugin.

Provide a Vulkan surface view base implementation

Provides a base implementation of the Vulkan surface view (VkSurfaceView.kt) and its accompanying components.

The implementation is meant to be extended and updated in order to integrate it with the existing Godot java and native codebase.

Drop old semaphore implementation

Fixes https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-02

Drop patch to disable VIA padlock since we no longer use libwebsockets,
so there's no conflict anymore.

Signals: Don't pass default binds to EditorProperty property_changed

This was done by mistake in #36758, but it's not necessary and actual
causes a bug.

`property_changed` is only emitted via `emit_changed()`, which already
has default values for `p_field` and `p_changing`.

Also reverted to using `String` for now to be on the safe side, even if
it's inconsistent with `emit_changed()`. I had only changed it
partially in #36758 so it was inconsistent. It probably does make sense
to port `EditorInspector` and related property editors to use
`StringName` where relevant, but that's for a dedicated PR.

Fixes #36799.

Change LINKFLAGS to FRAMEWORKS which is supported since Scons release 0.96.91

Fix possible EditorFolding crash when switching scenes

Fix some bugs spotted by asan in editor debugger.

EditorDebuggerInspector is in tree, so it gets automatically deleted,
when clearing errors the debugger should not fake a process
notification.

Add a new configuration warning to CollisionShape

ConfigFile: Improve error messages

In the case where a ConcavePolygonShape is used as a shape for a RigidBody
in another mode than static, a configuration warning will appear in the
editor.

Mono: Fix detection of Apple platforms in build script

Document EditorPlugin get_plugin_icon and get_plugin_name

Added to .gitignore - Cppcheck folder and Gcov, Lcov code coverage

Miscellaneous cleanup for the Android codebase

Remove '/permissive-' flag from Windows MSVC build

Tweak the GIProbe gizmo to be more subtle

Improve the GIProbe editor contextual label

The return value's type hint is now accurate.

- update gradle plugins versions
- add formatting rules for AndroidManifest and gradle build files
- cleanup java_godot_lib_jni

Note: logic was mostly moved around and no new logic/functionality was added.

Turn Rect2's 'intersects_touch()' into an extra argument of 'intersects()'

Vulkan: Use Godot print macros matching MessageSeverity flag