Cw 657 new buy sell flow (#1553)

* init commit

* onramper

* moonPay

* dfx provider

* meld

* dfx payment methods

* fiat buy credentials

* moonpay payment method

* payment loading state

* dfx sell quote

* onramper launch trade

* meld launch trade

* country picker

* update option tile

* buy/sell action

* meld refactor

* update pr_test_build.yml

* ui fixes

* revert country picker commit

* update the ui

* recommended providers

* payment method [skip ci]

* provider option tile

* remove buy action

* minor fixes

* update the best rate when the amount is changed

* fixes for currency title

* fix icons

* code refactoring

* null issue

* code review fixes

* Update pr_test_build_linux.yml

* Update meld_buy_provider.dart

* Update meld_buy_provider.dart

* add show wallets action

* remove default sell / buy provider setting

* localisation

* providerTypes

* icons

* remove duplicate file [skip ci]

* minor changes [skip ci]

* fixes from review

* disable dfx for non eur/chf currencies
fix providers to be fetched with the selected currency

* fix breaking from loop if one element failed

* fix minor naming issue from merging conflicts

* add fiat check for moonpay

* fix address validation

* merge conflict

* fix destination and source currency

* minor fix

* minor fix

* update the flow

* fix bch address format

* fix wallet addresses

* fix initial fetching amount.

* Update address_validator.dart

* review comments

* revert switch case to return null

* minor fix

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Co-authored-by: OmarHatem <omarh.ismail1@gmail.com>

lib/typography.dart

@@ -22,6 +22,8 @@ TextStyle textMediumSemiBold({Color? color}) => _cakeSemiBold(22, color);
 
 TextStyle textLarge({Color? color}) => _cakeRegular(18, color);
 
+TextStyle textLargeBold({Color? color}) => _cakeBold(18, color);
+
 TextStyle textLargeSemiBold({Color? color}) => _cakeSemiBold(24, color);
 
 TextStyle textXLarge({Color? color}) => _cakeRegular(32, color);