bash-completion: add support for recipe scripts

Define the scripts in the recipe with bash_completion
member variable to be sourced in shell command.

Add gst-inspect-1.0 and gst-launch-1.0 bash completion
support from gstreamer-1.0 recipe.
14 jobs for add_bash_completion in 201 minutes and 51 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Preparation
passed #391690
manifest

00:00:39

 
  Pre Build
passed #391692
cerbero deps android universal

00:57:54

passed #391691
cerbero deps fedora x86_64

00:40:43

passed #391696
gst-ios-12.2
cerbero deps ios universal

02:31:20

passed #391695
gst-macos-10.14
cerbero deps macos x86_64

00:59:00

passed #391693
cerbero deps windows x86

00:50:35

passed #391694
cerbero deps windows x86_64

00:34:03

 
  Build
passed #391698
cerbero android universal

00:14:28

passed #391699
cerbero cross win32

00:08:31

passed #391700
cerbero cross win64

00:05:39

passed #391697
cerbero fedora x86_64

00:06:01

passed #391702
gst-ios-12.2
cerbero ios universal

00:42:53

passed #391701
gst-macos-10.14
cerbero macos x86_64

00:07:28

 
  Integrate
passed #391703
cerbero android universal examples

00:06:57