#1774 Save to CDX converts aromatic benzene ring to dashed ring

[AliaksandrDziarkach]

Fix cdx bond load to set direction only for single bond. Fix UT

Generic request

• [ ] PR name follows the pattern #1234 – issue name
• [ ] branch name does not contain '#'
• [ ] base branch (master or release/xx) is correct
• [ ] PR is linked with the issue
• [ ] task status changed to "Code review"
• [ ] code follows product standards
• [ ] regression tests updated

  For release/xx branch

• [ ] backmerge to master (or newer release/xx) branch is created