Refactoring: delete_cross_elements_cache

[nkh]

It's defined in two places and not used at all.

• lib/App/Asciio/Cross.pm:189:5:sub delete_cross_elements_cache
• lib/App/Asciio/Actions/Elements.pm:141:8:$self->delete_cross_elements_cache();
• lib/App/Asciio/Actions/Elements.pm:138:5:sub delete_cross_elements_cache

[nkh]

@qindapao this one is for you to check

[qindapao]

@nkh

The code has been completely removed, please check