This reverts commit 82ad6be5.

We need to bump Rust to 1.45 for #40115 and thus, we need to back out
this patch again and try finding a fix for #40114 instead.

Update GeckoView part

application-services needs a newer Rust compiler as it now uses
features (strip_suffix()) that got stablizied in 1.45.0 first. We don't
want to risk GeckoView stability and thus bite the bullet and add a
different project solely used by application-services for the time being.
We omit the clean-up as this is supposed to be temporary until Rust for
GeckoView gets bumped.

It is noteworthy that we still need the patch for bug 43909 albeit in
a slightly updated fashion. Originally, this landed on trunk for the
10.0 release but it got backed out later on and did not reland in time
for any 10.0 release. Thus, we need to keep that patch until Rust
switches to LLVM 11.

As Fenix 82 uses clang 11.0.0-rc3 it is easier if we switch to using
the llvm-project repository directly. This fixes the mobile part of
bug 40048.

We need to use our compiled binutils version, too, as the one that comes
with Debian Buster (2.31.1) is breaking the build. We hit
https://bugs.llvm.org/show_bug.cgi?id=42994 which is essentially
an ld bug (https://sourceware.org/bugzilla/show_bug.cgi?id=24458). That
one is fixed on the 2.31 branch and onwards but never made it into a
2.31.x release.

We can drop our Windows patches now as the underlying bug
(https://sourceware.org/bugzilla/show_bug.cgi?id=17321) got fixed
in binutils 2.34.

See: https://bugzilla.mozilla.org/show_bug.cgi?id=1648555 for the
upstream bug.

I missed them on the server-side.

Updating glean_parser to 1.28.6 fixes the remaining part of #40086 as
well.

This compiles and links NSS/application-services with lto, and also adds a check
which will make the building of the application-services project fail if it finds
networking symbols in the final built libraries.

We take the shortcut and just overwrite all the geckoview .aar files in
our gradle-dependencies that are not breaking the build, which helps
with fenix#40017, too.

In addition, we delete the hard-coded Fenix specific `version` and we
use `abbrev`, instead.

We need to make sure we just set MOZ_BUILD_DATE and adapt the format
where it is actually needed. See: fenix#40059 for the Fenix part that
makes use of that to fix #40084.

We bump Fenix to 81.1.1 and android-components to 57.0.6 while GeckoView
is staying on 81.0b9 to save us another round of rebasing.

It turns out that declaring a `beta_version` and including that in the
version number for a branch name might not have been the best idea given
that not all our branches are based on mozilla-beta. So, we drop that
and add the beta version directly when needed.

We sort now in a way that makes the output reproducible on different
machines and exclude .module files, too, as we do not need them.

Versions bump and Changelog update

Additionally, we clean up our projects removing Linux workarounds not
needed under Jessie anymore.

CentOS 6 will be EOL later this year (Nov 2020). We are removing support
for it beginning with 10.5 which will get released around mid-2021.