Fixes#13729
Previously, when adding a window, we were unable to read its current
project paths out of the hash of the URL during window initialization
because the window still considered itself to be loading. Rather than
fixing this issue, we decided to completely eliminate the sharing of
state between processes in the window.location and instead switch to
cached synchronous RPC for the loadSettings and a dedicated RPC-based
mechanism for the project paths.
This is needed because some packages may still rely on the ability
to pass null/undefined to path.dirname and friends
Signed-off-by: Nathan Sobo <nathan@github.com>
