6383 dna antisense chains

[ALexanderSPB]

How the feature works? / How did you fix the issue?

(Screenshots, videos, or GIFs, if applicable)

Check list

• unit-tests written
• e2e-tests written
• documentation updated
• PR name follows the pattern #1234 – issue name
• branch name doesn't contain '#'
• PR is linked with the issue
• base branch (master or release/xx) is correct
• task status changed to "Code review"
• reviewers are notified about the pull request

[Zhirnoff]

I guess right screenshot is incorrect because tooltip cover all RNA Builder

[svvald]

It works good and the option to create a DNA antisense strand is present in context menu in sequence mode

However, this option is missing in flex/snake mode, there is only one option to create an antisense strand (RNA):

According to the feature requirements,

DNA antisense chain creation should be supported in all three macromolecules modes and can be executed either by choosing "Create DNA Antisense Strand" from the right-click drop-down menu after appropriate monomers are selected

@ALexanderSPB Could you please adjust it as well?