Upload logo (#54)

* add upload component for logo

* - move upload logo functionlity to its own component
- style upload logo component
- display current logo from server
- implement submit button on logo updater, to submit new logo to api after update
- add some submit status indicator

* update edit-logo component

Logo now posts correctly to owncast api endpoint. This update includes file type
validation and removes the submit button, since the ant.d Upload component
already handles the post logic.

* remove submit-button style for logo upload

Co-authored-by: gingervitis <omqmail@gmail.com>

web/utils/config-constants.tsx

@@ -79,7 +79,7 @@ export const TEXTFIELD_PROPS_LOGO = {
   placeholder: '/img/mylogo.png',
   label: 'Logo',
   tip:
-    'Name of your logo in the data directory. We recommend that you use a square image that is at least 256x256.',
+    'Upload your logo if you have one. We recommend that you use a square image that is at least 256x256.',
 };
 export const TEXTFIELD_PROPS_STREAM_KEY = {
   apiPath: API_STREAM_KEY,