Support template command

[lucklove]

To provide standard templates and detailed instructions in the template files

Close #1024

What problem does this PR solve?

When a new user wants to use TiUP to deploy a cluster, he may don't know how to write the topology file, so he must open the browser and find the example topology. This is no a good experience.

What is changed and how it works?

I add a template command for both tiup-cluster and tiup-dm, the command will print the topology templates:

tiup cluster template > topology.yaml
vim topology.yaml                                       # use the correct hosts
tiup cluster deploy test v4.0.0 topology.yaml

Check List

Tests

• Manual test (add detailed scripts or steps below)

Code changes

• Has exported function/method change
• Has exported variable/fields change
• Has interface methods change
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation

Release notes:

NONE

[codecov-io]

Codecov Report

Merging #1156 (82cc921) into master (d5ae317) will decrease coverage by 11.03%.
The diff coverage is 36.36%.

@@             Coverage Diff             @@
##           master    #1156       +/-   ##
===========================================
- Coverage   53.53%   42.49%   -11.04%     
===========================================
  Files         284      223       -61     
  Lines       20302    16057     -4245     
===========================================
- Hits        10868     6823     -4045     
- Misses       7756     8062      +306     
+ Partials     1678     1172      -506     

Flag	Coverage Δ
cluster	42.49% <36.36%> (-2.53%)	⬇️
dm	?
integrate	42.49% <36.36%> (-5.41%)	⬇️
playground	?
tiup	?
unittest	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
components/cluster/command/template.go	33.33% <33.33%> (ø)
components/cluster/command/root.go	46.82% <100.00%> (+0.30%)	⬆️
pkg/repository/store/store.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/repository/utils/hash.go	0.00% <0.00%> (-81.82%)	⬇️
pkg/meta/err.go	0.00% <0.00%> (-81.25%)	⬇️
pkg/telemetry/meta.go	0.00% <0.00%> (-80.00%)	⬇️
pkg/telemetry/scrub.go	6.66% <0.00%> (-80.00%)	⬇️
pkg/cluster/api/error.go	0.00% <0.00%> (-80.00%)	⬇️
pkg/repository/store/local.go	0.00% <0.00%> (-76.48%)	⬇️
pkg/repository/model/publish.go	0.00% <0.00%> (-71.43%)	⬇️
... and 142 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d5ae317...82cc921. Read the comment docs.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• AstroProfundis

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by writing /lgtm in a comment.
Reviewer can cancel approval by writing /lgtm cancel in a comment.

[AstroProfundis]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 82cc921