make some region_command support jq

[fredchenbj]

What problem does this PR solve?

make some region_command, such as region topwrite support --jq.

Tests

• Manual test

Side effects

bin/pd-ctl -u http://10.136.133.23:2379 -d region topwrite 1 --jq=".regions[] | {start_key: .start_key, end_key: .end_key, peer_stores: [.peers[].store_id], leader:.leader.store_id, id: .id, written_bytes: .written_bytes}"
unknown flag: --jq
{"start_key":"fm_bench_mark_user:-1254349631","end_key":"fm_bench_mark_user:-1256054961","peer_stores":[17,8,1],"leader":17,"id":86367,"written_bytes":28664496}

See above, it ouputs unexpected message "unknown flag: --jq".

[sre-bot]

Hi contributor, thanks for your PR.

This patch needs to be approved by someone of admins. They should reply with "/ok-to-test" to accept this PR for running test automatically.

[sre-bot]

Hi contributor, thanks for your PR.

This patch needs to be approved by someone of admins. They should reply with "/ok-to-test" to accept this PR for running test automatically.

[CLAassistant]

All committers have signed the CLA.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@8d6c936). Click here to learn what that means.
The diff coverage is 42.3%.

@@            Coverage Diff            @@
##             master    #1420   +/-   ##
=========================================
  Coverage          ?   67.44%           
=========================================
  Files             ?      157           
  Lines             ?    14820           
  Branches          ?        0           
=========================================
  Hits              ?     9996           
  Misses            ?     3892           
  Partials          ?      932

Impacted Files	Coverage Δ
tools/pd-ctl/pdctl/command/region_command.go	46.76% <42.3%> (ø)

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[nolouch]

LGTM! thanks

[rleungx]

LGTM.