feat(client): ts-migrate footer (#42636)

Co-authored-by: Parth Parth <thecodingaviator@users.noreply.github.com>

client/src/components/Footer/footer.test.tsx

@@ -1,7 +1,7 @@
 import React from 'react';
 import renderer from 'react-test-renderer';
 
-import Footer from './';
+import Footer from '.';
 
 describe('<Footer />', () => {
   it('matches snapshot', () => {

client/src/components/Footer/index.tsx

@@ -1,21 +1,21 @@
 import React from 'react';
-import PropTypes from 'prop-types';
 import { useTranslation } from 'react-i18next';
 import Link from '../helpers/link';
 import './footer.css';
 
-const propTypes = {
-  children: PropTypes.any
+type ColHeaderProps = {
+  children: string | React.ReactNode | React.ReactElement;
 };
 
-const ColHeader = ({ children, ...other }) => (
+// TODO: Figure out what ColHeader does: 'ColHeader' is declared but its value is never read.
+// eslint-disable-next-line
+const ColHeader = ({ children, ...other }: ColHeaderProps): JSX.Element => (
   <div className='col-header' {...other}>
     {children}
   </div>
 );
-ColHeader.propTypes = propTypes;
 
-function Footer() {
+function Footer(): JSX.Element {
   const { t } = useTranslation();
 
   return (

client/src/components/helpers/link.tsx

@@ -8,8 +8,6 @@ interface LinkProps {
   sameTab?: boolean;
   state?: Record<string, unknown>;
   to: string;
-  // TODO: figure out what these actually should be
-  other?: unknown[];
 }
 
 const Link = ({