[FIX] web: Allow user to download binary file in always edit mode

Steps:
- Open studio in any form view
- Add Binary Field
- Close Studio
- Upload a file in the previously added binary field
- We can't download it because of always edit

This commit adds a new download button near edit and clear button

opw-3028094

closes odoo/odoo#104961

X-original-commit: 73a2329b8bf4e887890cae7669bc568ae0be7147
Signed-off-by: Luca Vitali <luvi@odoo.com>

addons/web/static/src/views/fields/binary/binary_field.xml

@@ -9,6 +9,14 @@
                         acceptedFileExtensions="props.acceptedFileExtensions"
                         onUploaded.bind="update"
                     >
+                        <t if="props.record.resId">
+                            <button
+                                class="btn btn-secondary fa fa-download"
+                                data-tooltip="Download"
+                                aria-label="Download"
+                                t-on-click="onFileDownload"
+                            />
+                        </t>
                         <t t-set-slot="toggler">
                             <input type="text" class="o_input" t-att-value="fileName" readonly="readonly" />
                             <button

addons/web/static/tests/views/fields/binary_field_tests.js

@@ -144,7 +144,7 @@ QUnit.module("Fields", (hooks) => {
     });
 
     QUnit.test("BinaryField is correctly rendered", async function (assert) {
-        assert.expect(9);
+        assert.expect(12);
 
         async function send(data) {
             assert.ok(data instanceof FormData);
@@ -205,6 +205,22 @@ QUnit.module("Fields", (hooks) => {
             "the filename field should have the file name as value"
         );
 
+        // Testing the download button in the field
+        // We must avoid the browser to download the file effectively
+        const prom = makeDeferred();
+        const downloadOnClick = (ev) => {
+            const target = ev.target;
+            if (target.tagName === "A" && "download" in target.attributes) {
+                ev.preventDefault();
+                document.removeEventListener("click", downloadOnClick);
+                prom.resolve();
+            }
+        };
+        document.addEventListener("click", downloadOnClick);
+        registerCleanup(() => document.removeEventListener("click", downloadOnClick));
+        await click(target.querySelector(".fa-download"));
+        await prom;
+
         await click(target.querySelector(".o_field_binary .o_clear_file_button"));
 
         assert.isNotVisible(