global: Fixes strings marked for translation.

- Removes superfluous white space.
- Adjust field to look like other fields.

Refs: inveniosoftware/invenio-app-rdm#1707

invenio_communities/assets/semantic-ui/js/invenio_communities/members/invitations/invitationsModal/MemberSearchBar.js

@@ -179,5 +179,5 @@ MembersSearchBar.propTypes = {
 };
 
 MembersSearchBar.defaultProps = {
-  placeholder: i18next.t("Search ..."),
+  placeholder: i18next.t("Search..."),
 };

invenio_communities/assets/semantic-ui/js/invenio_communities/settings/profile/RenameCommunitySlugButton.js

@@ -90,7 +90,8 @@ export class RenameCommunitySlugButton extends Component {
           <Modal.Content>
             <Form onSubmit={this.handleChange}>
               <Form.Input
-                label={i18next.t("Enter the new unique identifier of the community.")}
+                label={i18next.t("New unique identifier of the community")}
+                placeholder={i18next.t("New unique identifier of the community")}
                 fluid
                 input={{ ref: this.formInputRef }}
                 {...(error