fix(load): fix window load timing
fix(load): fix window load timing

Summary:
The app regressed to launching a blank white page for a while before
showing the UI. This was because I forgot to await for the now async
package loading

Test Plan: Manually boot app with compile cache disabled

Reviewers: mark, spang, juan

Reviewed By: juan

Differential Revision: https://phab.nylas.com/D3883

nirmit/nylas-mail,simonft/nylas-mail,simonft/nylas-mail,nylas-mail-lives/nylas-mail,nirmit/nylas-mail,nylas-mail-lives/nylas-mail,nirmit/nylas-mail,simonft/nylas-mail,nirmit/nylas-mail,simonft/nylas-mail,nylas/nylas-mail,nylas/nylas-mail,nylas/nylas-mail,nylas-mail-lives/nylas-mail,simonft/nylas-mail,nylas-mail-lives/nylas-mail,nylas/nylas-mail,nirmit/nylas-mail,nylas/nylas-mail,nylas-mail-lives/nylas-mail