T6823: correctly set the IPv6 autoconf option (#433)

• T6823 init fix

• slaac and integration tests

• reaplced integration test

• WIP integration tests

• changelog and tweaks

• rendered, gathered, parsed, integration tests for SLAAC

• l3_interfaces gathered, emty, deleted

• deleted integration test

• vif processing

• vif tests

• vir related integration test cases

• ignore ansible-bad-import-from

• ansible-bad-import-from ingore

• ignore ansible-bad-import-from for all

• test ansible-bad-import-from skip

• ingore file

• Fix bugs with configuration remove

• Delete testcase fixed

• SLAAC integration tests

• Sanity check fixes

• remove_config formatted

• l3 slaac eth0 removed from SIT

• Remove ignore 2.20

• ignore2.20 recovered

• Remove residue