feat: improve UI for timespan inputs on admin page (#726)

* Define Timestamp type

* Implement Timestamp utils

* Implement Timespan input

* Use timestamp input on config page

* Add timespan type to config services

* Refactor maxExpiration to use timespan type across services and components

* Update sessionDuration to use timespan type in config and adjust token expiration logic

* Update localized strings

backend/src/share/share.service.ts

@@ -56,12 +56,13 @@ export class ShareService {
 
       const expiresNever = moment(0).toDate() == parsedExpiration;
 
+      const maxExpiration = this.config.get("share.maxExpiration");
       if (
-        this.config.get("share.maxExpiration") !== 0 &&
+        maxExpiration.value !== 0 &&
         (expiresNever ||
           parsedExpiration >
             moment()
-              .add(this.config.get("share.maxExpiration"), "hours")
+              .add(maxExpiration.value, maxExpiration.unit)
               .toDate())
       ) {
         throw new BadRequestException(