Unbounded loops in RemoteBackend.ts

[vitvakatu]

We have two places in RemoteBackend.ts with unbounded infinite loops that can get stuck due to backend or connectivity issues.

• enso/app/common/src/services/RemoteBackend.ts

  Line 968 in 915009a

  while (true) {

• enso/app/common/src/services/RemoteBackend.ts

  Line 1562 in 915009a

  while (true) {

We need to guard these places with reasonable timeouts.