Fix cmds requesting too quickly in a loop uids from pubkey with BMA (#438)

Specially happening in local condition, where there is no network latency

• blocks, history -u, and transfer commands
• Define BMA_SLEEP constant to 0.1 second
• Set time.sleep(BMA_SLEEP) between the requests

Close #438 (closed), #3 (closed).

changed milestone to %0.11.0

added API: BMA Bug Network labels

requested review from @moul

assigned to @moul

approved this merge request

merged