[beta] Backports (#6163)

* Light client improvements (#6156)

* no seal checking

* import command and --no-seal-check for light client

* fix eth_call

* tweak registry dapps lookup

* ignore failed requests to non-server peers

* Fix connecting to wildcard addresses. (#6167)

* Don't display an overlay in case the time sync check fails. (#6164)

* Small improvements to time estimation.

* Temporarily disable NTP time check by default.