* Update price display
As proposed by @dstrukt in #4364.
* Update format
* Unify price display across the app
* Add DisplayFormatter
* Replace DisplayFormatCurrency method
* Use symbol currency format for invoice
* Unify currency formats on backend pages
* Revert recent changes
* Do not show exchange rate and fiat order amount for crypto denominations
* Fix test and add test cases
replaces #1591 and #1592 , closes#1571 Replaces the Currencies.txt to a json format which includes the networks too ( there is also a test to check now) Also makes CurrencyPair not depend on network and instead use CurrencyNameTable