root: function declaration clean-up

Following this discussion, this MR standardise function declaration. For now on, every named function should have the following pattern:

function Name (): ReturnType {

arrow declarations can still be used, but are limited to in-line utilisation similar to:

list.map((item) => { item.title })
onClick={(): void => changeMonth(true)}

Some examples

-  const handleDrop = function (e: any): void {
+  function handleDrop (e: any): void {

-  const makeOnClickFilterTeam = (item: string) => () => {
+  function makeOnClickFilterTeam (item: string) {

-  function handleClick = async (): Promise<void> => {
+  async function handleClick (): Promise<void> {

-  export const coloredAppButtonClasses = function(): string =>
    twMerge("...")
+  export const coloredAppButtonClasses: string = twMerge("...")

Additional changes

• updated all package.json to have the same version of common packages (vite, typescript, eslint, etc)
• completed several function return types
• removed several deprecated icons and components (left Modal and SmoothScrollToTopWrapper as they might need refactoring)
• sorted and reorganise imports
• added space before function declaration and returns (manually, so no that consistent)