support labels when using fieldtoappend feature

[nikosn]

Description

Add labels when the fieltoappend feature is used.

Fixes #207

Type of change

Please delete options that are not relevant.

• [x ] New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Using fieldtoappend with labels is successfully tested in production.

Checklist:

The code change is trivial.