Changes

testenv: use new osmocom-bb binary packages

When using --binary-packages, use the osmocom-bb-trxcon etc. binary
packages that are now available, instead of only installing the
dependencies as binary packages and building these components from
source.

Change-Id: I072ea55d12060b4ef04ee9775ef116d553090e9a

SGSN_Tests: f_TC_attach_usim_resync: fix IMEISV value

IMEISV is IMEI + 2 digit software version.

Change-Id: I044eeccd02e2d3f891879516f5a9c003ac8f849a

PCU_Tests_SNS: SNS Add: handle NS_Alive while waiting for SNS_Ack

Similiar to 61ccea9ecadc ("PCU_Tests_SNS: del/change weight: don't fail on NS"),
the SNS Add procedure might have to handle a NS Alive PDU in the receiving queue while waiting
for a SNS ACK.

Related: OS#6611
Change-Id: I10646d9acfe280ddfb8852a4d5c37882aae99874

testenv: make copy= more intuitive

Currently copy= in testenv.cfg creates copies of files under the full
source file name under the target directory: copy=dir/file.cfg creates
dir/file.cfg (like "cp -a --parents"). This is not very intuitive,
change it to create a "file.cfg" instead without subdirectory. With
this change, it behaves the same as "cp -a".

Suggested-by: Pau Espin Pedrol <pespin@sysmocom.de>
Change-Id: Id9e4ea066d0a0e72ccd83e4f6f887f382bf61e46

remsim: Add initial testenv

"server" testsuite is working as goos as in docker-playground.git
"bankd" testsuite is currently failing due to bankd exiting early after
starting.
"client" is not currently working/running in docker-playground, initial
config copied here for completeness.

This commit hence allows already quickly running "server" testsuite.

Change-Id: Ic69a04342a4cdfced90cf8ffbe7e5cdede8d4b8e