uri-source: Respect stream-id even on streams muxed in raw

The issue is that we rely on `decodebin::autoplug-select` to `SKIP`
unwanted pads, that signal was first provided to select factories during
autoplugin, not totally thought to avoid exposing pads. For streams
muxed directly in raw, decodebin has nothing to plug after the demuxer
and the pad is exposed right away, meaning that we do not have any
chance to avoid that pad to be exposed. This patch takes that limitation
into account and checks the stream ID of the pads exposed by decodebin
before exposing them itself, so we end up using the right pad even if
more are uselessly exposed by decodebin.

Fixes gstreamer/gst-editing-services#126

Part-of: <gstreamer/gst-editing-services!222>
33 jobs for !222 with ensure_stream_id_respected in 32 minutes and 26 seconds (queued for 4 seconds)
detached
Status Job ID Name Coverage
  Build Docker
passed #6837027
alpine amd64 manifest builder docker

00:00:24

passed #6837025
android docker

00:00:15

passed #6837023
cerbero fedora amd64 docker

00:00:24

passed #6837022
fedora amd64 docker

00:00:24

passed #6837028
gst-indent amd64 docker

00:00:14

 
  Preparation
passed #6837033
check allow-edit

00:00:19

passed #6837032
gst indent

00:00:16

passed #6837030
manifest

00:00:25

 
  Build
passed #6837050
gstreamer
build cerbero cross-android universal

00:07:07

passed #6837058
gst-ios-14.3
build cerbero cross-ios universal

00:19:56

passed #6837052
gstreamer
build cerbero cross win32

00:05:47

passed #6837054
gstreamer
build cerbero cross win64

00:05:49

passed #6837048
gstreamer
build cerbero fedora x86_64

00:05:55

passed #6837057
gst-macos-11.1
build cerbero macos x86_64

00:10:43

passed #6837059
docker windows 1809 gstreamer-windows
build cerbero msvc x86_64

00:12:08

passed #6837040
build clang fedora x86_64

00:03:45

manual #6837046
docker windows 1809 allowed to fail manual
build msys2
passed #6837035
build nodebug fedora x86_64

00:04:31

passed #6837036
build static fedora x86_64

00:04:31

passed #6837038
build static nodebug fedora x86_64

00:04:31

passed #6837041
docker windows 1809
build vs2017 amd64

00:09:24

passed #6837043
docker windows 1809
build vs2017 x86

00:09:43

 
  Test
passed #6839269
gstreamer
check fedora

00:05:13

passed #6837061
gstreamer
integration testsuites fedora 1/4

00:14:45

passed #6837062
gstreamer
integration testsuites fedora 2/4

00:14:39

passed #6837063
gstreamer
integration testsuites fedora 3/4

00:13:09

passed #6837064
gstreamer
integration testsuites fedora 4/4

00:15:52

passed #6837065
gstreamer
valgrind ges

00:06:13

failed #6837060
gstreamer
check fedora

00:07:37

 
  Integrate
passed #6837066
cross-android universal examples

00:06:57

passed #6839270
gst-ios-14.3
cross-ios universal examples

00:03:54

passed #6837067
documentation

00:11:26

failed #6837068
gst-ios-14.3
cross-ios universal examples

00:03:35