LabelOptionsAwareInterface => LabelAwareInterface

this should not be a BC break because the interface is not included in
any release yet, change only affect develop branch
add disable_html_escape label option support to FormCollection helper
minor code cleaning
fix typo and missing use
Merge pull request #5910 from stefanotorresi/improvement/form-labels

minor improvements to form labels
Merge branch 'feature/5910' into develop

Close #5910