videoaggregator: Emit "buffer-consumed" right when it is consumed

And make sure that it is emited without the GstAggregator object lock
taken, otherwise no property can be set on the pad in the signal
callback.
17 jobs for vagg_buffer_consumed in 58 minutes and 42 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Preparation
passed #309175
gst indent

00:00:34

passed #309174
manifest

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  Build
passed #309176
build fedora x86_64

00:05:22

passed #309177
build nodebug fedora x86_64

00:04:40

 
  Test
passed #309178
check fedora

00:03:51

passed #309179
integration testsuites fedora

00:10:05

 
  Full Builds
passed #309181
build cerbero android universal

00:12:58

passed #309182
build cerbero cross win32

00:07:24

passed #309183
build cerbero cross win64

00:06:07

passed #309180
build cerbero fedora x86_64

00:06:00

 
  Full Tests
passed #309187
valgrind bad

00:07:23

passed #309184
valgrind base

00:19:10

passed #309188
valgrind ges

00:03:55

passed #309185
valgrind good

00:09:05

passed #309186
valgrind ugly

00:02:15

 
  Apps
passed #309189
android universal examples

00:06:51

 
  Deploy
passed #309190
documentation

00:03:14