feat(miner): friendlier miner output

[sdbondi]

Description

Cleans up the miner output:

• output warn level to console output
• use emojis for miner reports
• change connect via grpc messages to info level

Motivation and Context

The miner would start with two red error messages that showed successful connections to the wallet and base node.
This PR cleans that up and adds emojis.

11:03 INFO  🔗 Connecting to base node at 127.0.0.1:18142
11:03 INFO  👛 Connecting to wallet at 127.0.0.1:18143
11:03 INFO  ⛏ Miner 0 reported 0.91MH/s with total 9.15MH/s over 10 threads. Height: 32. Target: 344194565)
11:03 INFO  ⛏ Miner 3 reported 0.59MH/s with total 5.94MH/s over 10 threads. Height: 32. Target: 344194565)
11:03 INFO  ⛏ Miner 5 reported 0.84MH/s with total 8.44MH/s over 10 threads. Height: 32. Target: 344194565)
11:03 INFO  ⛏ Miner 4 reported 0.77MH/s with total 7.69MH/s over 10 threads. Height: 32. Target: 344194565)
11:03 INFO  ⛏ Miner 6 reported 0.81MH/s with total 8.08MH/s over 10 threads. Height: 32. Target: 344194565)
11:03 INFO  ⛏ Miner 1 reported 0.79MH/s with total 7.86MH/s over 10 threads. Height: 32. Target: 344194565)
11:03 INFO  ⛏ Miner 2 reported 0.79MH/s with total 7.89MH/s over 10 threads. Height: 32. Target: 344194565)
11:03 INFO  ⛏ Miner 7 reported 0.79MH/s with total 7.91MH/s over 10 threads. Height: 32. Target: 344194565)
11:04 INFO  ⛏ Miner 9 reported 0.80MH/s with total 8.05MH/s over 10 threads. Height: 32. Target: 344194565)
11:04 INFO 💰 Found block

How Has This Been Tested?

Manually

[CjS77]

LGTM, but It shouldn't be necessary to dupe messages (i.e. println + log). This should really be user-directed, and in fact, The logging backend is able to do this already.

log4rs is configurable to (for eg) direct info+ to stdout, while piping all messages to foo.log.

[sdbondi]

Fair enough, will go that route