Make a good part of the app localizable and add French translations (#325)

Co-authored-by: Yohan Boniface <yohanboniface@free.fr>

app/client/ui2018/modals.ts

@@ -1,4 +1,5 @@
 import {FocusLayer} from 'app/client/lib/FocusLayer';
+import {makeT} from 'app/client/lib/localization';
 import {reportError} from 'app/client/models/errors';
 import {cssInput} from 'app/client/ui/cssInput';
 import {prepareForTransition, TransitionWatcher} from 'app/client/ui/transitions';
@@ -11,6 +12,8 @@ import {Computed, Disposable, dom, DomContents, DomElementArg, input, keyframes,
   MultiHolder, Observable, styled} from 'grainjs';
 import {cssMenuElem} from 'app/client/ui2018/menus';
 
+const t = makeT('ui2018.modals');
+
 // IModalControl is passed into the function creating the body of the modal.
 export interface IModalControl {
   // Observable for whether there is work in progress that's delaying the closing of the modal. It
@@ -303,13 +306,13 @@ export function saveModal(createFunc: (ctl: IModalControl, owner: MultiHolder) =
       cssModalTitle(options.title, testId('modal-title')),
       cssModalBody(options.body),
       cssModalButtons(
-        bigPrimaryButton(options.saveLabel || 'Save',
+        bigPrimaryButton(options.saveLabel || t('Save'),
           dom.boolAttr('disabled', isSaveDisabled),
           dom.on('click', save),
           testId('modal-confirm'),
         ),
         options.extraButtons,
-        options.hideCancel ? null : bigBasicButton('Cancel',
+        options.hideCancel ? null : bigBasicButton(t('Cancel'),
           dom.on('click', () => ctl.close()),
           testId('modal-cancel'),
         ),
@@ -423,7 +426,7 @@ export function invokePrompt(
   const prom = new Promise<string|undefined>((resolve) => {
     onResolve = resolve;
   });
-  promptModal(title, onResolve!, btnText ?? 'Ok', initial, placeholder, () => {
+  promptModal(title, onResolve!, btnText ?? t('Ok'), initial, placeholder, () => {
     if (onResolve) {
       onResolve(undefined);
     }