*: refine dumpling log hint system

[lichunzhu]

What problem does this PR solve?

1. close dumpling should fail when provided positional parameters to CLI #225. Dumpling won't check unparsed arguments now. It's not easy for users to find spell errors.
2. The speed of dumpling data from tidb to s3 drops 2+GBit/s to 200Mbit/s #223. Some logs in dumpling are not clear enough. For example, we print the estimated count without table name. It's hard to debug.
3. Users can't get current dumpling work status and progress from logs now.

What is changed and how it works?

1. Check unparsed arguments and return an error to users.
2. Refine dumpling's log info and adjust some log's level.
3. Add status printer in dumper.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

1. example for unparsed arguments:

$ ./bin/dumpling -P 4000 -T test.order_line -r 20 -F 10B where "id<5"
Release version: v4.0.8-31-gd75dc72
Git commit hash: d75dc721dd44902ea6fc72aafef88aad59977647
Git branch:      setWarnLog
Build timestamp: 2020-12-30 07:34:11Z
Go version:      go version go1.13.4 darwin/amd64

meet some unparsed arguments, please check again: [where id<5]

3. example for status printer:

[2020/12/30 16:42:22.197 +08:00] [INFO] [status.go:37] [progress] [tables="0/1 (0.0%)"] ["finished rows"=42191631] ["finished size"=7.764GB] ["average speed(MiB/s)"=61.70014464561885]
[2020/12/30 16:44:22.197 +08:00] [INFO] [status.go:37] [progress] [tables="0/1 (0.0%)"] ["finished rows"=86052795] ["finished size"=15.83GB] ["average speed(MiB/s)"=64.1418352230345]

Related changes

• Need to cherry-pick to the release branch

Release note

• support check un-recognized arguments and print current progress during dumping

[tangenta]

LGTM