* transaction-pool: expose blocking api for tx submission

* service: separate ServiceBuilder::build for full and light

* service: add ServiceBuilder::build_common

* transaction-pool: extend docs

Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>