kamailio-5.x: bump to 5.4.0

kamailio-5.x: bump to 5.4.0

- package two new modules: dlgs and pv_headers
- upstream actually provides three more new modules, but two are missing
  dependencies in OpenWrt and one is related to systemd
- use INSTALL_DATA instead of INSTALL_CONF for kamailio configuration
  files (not talking about /etc/config/kamailio) as they're default
  configuration
- refresh 050-fix-kamailio-utils.patch
- drop upstreamed 150-python3-cross-compile.patch
- libsrutils is no longer packaged as upstream moved it into the core

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>