This update for yast2, yast2-installation-control, yast2-update, and yast2-pkg-bindings fixes the following issues:

yast2:

- Fixed `Resolvables class` to uniquely identify the libzypp objects to avoid random failures (bsc#1178688)

yast2-installation-control:

- Allowing the change of vendor without user interaction. (jsc#SLE-14807, jsc#SLE-15184)

yast2-pkg-bindings:

- Allow filtering resolvables by RPM path, return RPM path for the product packages (bsc#1178688, bsc#1176276)
- Set the previous `distro_target` option when restarting the package manager (bsc#1176275)
- Expand the URL when libzypp expects it and avoid wrong repository name generated during installation. (bsc#1173509)
- Allowing the change of vendor without user interaction. (jsc#SLE-14807, jsc#SLE-15184)

yast2-update:

- Extended the list of compatible vendors. (jsc#SLE-14807)
- Fixed selecting the base product (e.g. SLES) during upgrade. (bsc#1176276, bsc#1176275)

This update was imported from the SUSE:SLE-15-SP2:Update update project.