Add USD serie in block fee/reward charts

frontend/src/app/shared/pipes/fiat-shortener.pipe.ts

@@ -0,0 +1,37 @@
+import { formatCurrency, getCurrencySymbol } from '@angular/common';
+import { Inject, LOCALE_ID, Pipe, PipeTransform } from '@angular/core';
+
+@Pipe({
+  name: 'fiatShortener'
+})
+export class FiatShortenerPipe implements PipeTransform {
+  constructor(
+    @Inject(LOCALE_ID) public locale: string
+  ) {}
+
+  transform(num: number, ...args: any[]): unknown {
+    const digits = args[0] || 1;
+    const unit = args[1] || undefined;
+
+    if (num < 1000) {
+      return num.toFixed(digits);
+    }
+
+    const lookup = [
+      { value: 1, symbol: '' },
+      { value: 1e3, symbol: 'k' },
+      { value: 1e6, symbol: 'M' },
+      { value: 1e9, symbol: 'G' },
+      { value: 1e12, symbol: 'T' },
+      { value: 1e15, symbol: 'P' },
+      { value: 1e18, symbol: 'E' }
+    ];
+    const rx = /\.0+$|(\.[0-9]*[1-9])0+$/;
+    const item = lookup.slice().reverse().find((item) => num >= item.value);
+
+    let result = item ? (num / item.value).toFixed(digits).replace(rx, '$1') : '0';
+    result = formatCurrency(parseInt(result, 10), this.locale, getCurrencySymbol('USD', 'narrow'), 'USD', '1.0-0');
+
+    return result + item.symbol;
+  }
+}