[FAB-14324] simplify committer config callback
[FAB-14324] simplify committer config callback

- remove committer from peer.Channel
- change signature of Channel#setConfigBlock to return an error
- pass Channel#setConfigBlock to NewLedgerCommitterReactive

Change-Id: Ic036b7e60732206ce5fff2b7fd9a2922c36aed8d
Signed-off-by: Matthew Sykes <89c6e4c9c1046731a9c37abefc223a83de36a5d9@us.ibm.com>

manish-sethi/fabric-sidedb,muralisrini/fabric,stemlending/fabric,manish-sethi/fabric-sidedb,stemlending/fabric,muralisrini/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,hyperledger/fabric,muralisrini/fabric,manish-sethi/fabric,stemlending/fabric,jimthematrix/fabric,binhn/fabric,binhn/fabric,binhn/fabric,stemlending/fabric,manish-sethi/fabric,jimthematrix/fabric,hyperledger/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb