Upgrade TypeScript and core-js

(cherry picked from commit 148480909917f69ff3b2ca547ccb4716dd56606e)

Closes #5306

frontend/src/Store/Selectors/createArtistAlbumsSelector.ts

@@ -1,4 +1,5 @@
 import { createSelector } from 'reselect';
+import AlbumAppState from 'App/State/AlbumAppState';
 import AppState from 'App/State/AppState';
 import Artist from 'Artist/Artist';
 import { createArtistSelectorForHook } from './createArtistSelector';
@@ -7,7 +8,7 @@ function createArtistAlbumsSelector(artistId: number) {
   return createSelector(
     (state: AppState) => state.albums,
     createArtistSelectorForHook(artistId),
-    (albums, artist = {} as Artist) => {
+    (albums: AlbumAppState, artist = {} as Artist) => {
       const { isFetching, isPopulated, error, items } = albums;
 
       const filteredAlbums = items.filter(

frontend/src/Store/Selectors/createArtistMetadataProfileSelector.ts

@@ -1,13 +1,14 @@
 import { createSelector } from 'reselect';
 import AppState from 'App/State/AppState';
 import Artist from 'Artist/Artist';
+import MetadataProfile from 'typings/MetadataProfile';
 import { createArtistSelectorForHook } from './createArtistSelector';
 
 function createArtistMetadataProfileSelector(artistId: number) {
   return createSelector(
     (state: AppState) => state.settings.metadataProfiles.items,
     createArtistSelectorForHook(artistId),
-    (metadataProfiles, artist = {} as Artist) => {
+    (metadataProfiles: MetadataProfile[], artist = {} as Artist) => {
       return metadataProfiles.find((profile) => {
         return profile.id === artist.metadataProfileId;
       });

frontend/src/Store/Selectors/createArtistQualityProfileSelector.ts

@@ -1,13 +1,14 @@
 import { createSelector } from 'reselect';
 import AppState from 'App/State/AppState';
 import Artist from 'Artist/Artist';
+import QualityProfile from 'typings/QualityProfile';
 import { createArtistSelectorForHook } from './createArtistSelector';
 
 function createArtistQualityProfileSelector(artistId: number) {
   return createSelector(
     (state: AppState) => state.settings.qualityProfiles.items,
     createArtistSelectorForHook(artistId),
-    (qualityProfiles, artist = {} as Artist) => {
+    (qualityProfiles: QualityProfile[], artist = {} as Artist) => {
       return qualityProfiles.find(
         (profile) => profile.id === artist.qualityProfileId
       );

frontend/src/Utilities/Date/getRelativeDate.ts

@@ -6,15 +6,33 @@ import isTomorrow from 'Utilities/Date/isTomorrow';
 import isYesterday from 'Utilities/Date/isYesterday';
 import translate from 'Utilities/String/translate';
 
-function getRelativeDate(date, shortDateFormat, showRelativeDates, { timeFormat, includeSeconds = false, timeForToday = false } = {}) {
+interface GetRelativeDateOptions {
+  timeFormat?: string;
+  includeSeconds?: boolean;
+  timeForToday?: boolean;
+}
+
+function getRelativeDate(
+  date: string | undefined,
+  shortDateFormat: string,
+  showRelativeDates: boolean,
+  {
+    timeFormat,
+    includeSeconds = false,
+    timeForToday = false,
+  }: GetRelativeDateOptions = {}
+) {
   if (!date) {
-    return null;
+    return '';
   }
 
   const isTodayDate = isToday(date);
 
   if (isTodayDate && timeForToday && timeFormat) {
-    return formatTime(date, timeFormat, { includeMinuteZero: true, includeSeconds });
+    return formatTime(date, timeFormat, {
+      includeMinuteZero: true,
+      includeSeconds,
+    });
   }
 
   if (!showRelativeDates) {