Bisq markets: Display terms of service and language selector (except on official markets).

refs #510

frontend/src/app/components/language-selector/language-selector.component.html

@@ -0,0 +1,5 @@
+<div [formGroup]="languageForm" class="text-small text-center mt-4">
+    <select formControlName="language" class="custom-select custom-select-sm form-control-secondary form-control mx-auto" style="width: 130px;" (change)="changeLanguage()">
+        <option *ngFor="let lang of languages" [value]="lang.code">{{ lang.name }}</option>
+    </select>
+</div>

frontend/src/app/components/language-selector/language-selector.component.ts

@@ -0,0 +1,48 @@
+import { DOCUMENT } from '@angular/common';
+import { ChangeDetectionStrategy, Component, Inject, OnInit } from '@angular/core';
+import { FormBuilder, FormGroup } from '@angular/forms';
+import { Language, languages } from 'src/app/app.constants';
+import { StateService } from 'src/app/services/state.service';
+
+@Component({
+  selector: 'app-language-selector',
+  templateUrl: './language-selector.component.html',
+  styleUrls: ['./language-selector.component.scss'],
+  changeDetection: ChangeDetectionStrategy.OnPush
+})
+export class LanguageSelectorComponent implements OnInit {
+  languageForm: FormGroup;
+  languages: Language[];
+
+  constructor(
+    private formBuilder: FormBuilder,
+    private stateService: StateService,
+    @Inject(DOCUMENT) private document: Document
+  ) { }
+
+  ngOnInit() {
+    this.languages = languages;
+
+    this.languageForm = this.formBuilder.group({
+      language: ['']
+    });
+    this.setLanguageFromUrl();
+  }
+
+  setLanguageFromUrl() {
+    const urlLanguage = this.document.location.pathname.split('/')[1];
+    if (this.languages.map((lang) => lang.code).indexOf(urlLanguage) > -1) {
+      this.languageForm.get('language').setValue(urlLanguage);
+    } else {
+      this.languageForm.get('language').setValue('en');
+    }
+  }
+
+  changeLanguage() {
+    const language = this.languageForm.get('language').value;
+    try {
+      document.cookie = `lang=${language}; expires=Thu, 18 Dec 2050 12:00:00 UTC; path=/`;
+    } catch (e) { }
+    this.document.location.href = `/${language}/${this.stateService.network}`;
+  }
+}