409 status code - Duplicate-Invoice error

@eCloud @Adithya_Raviraja @mkw @Malik @sameer @Maala @pmohdameen @mohdzeeshan5c0 @Hadi @rudyzidan @Arratech @BEX @plasker @y.khraishi @abin @m.alnoursi @sameer @mohammad.mt

Dear All,
If you have any concerns on the new front end duplication validation rules (208 for Clearance and 409 for Reporting), please share them on the main thread below or here.