schedule/placement/fit: cache the match info for rules to peers

[AndreMouche]

What problem does this PR solve?

Issue Number: Close #5276

Check List

Tests

• Unit test

• benchmark

current branch

➜  placement git:(fit_cache) ✗ go test -benchmem -run=^$ -bench ^BenchmarkFitRegionWithMoreRulesAndStoreLabels -benchtime=100x
goos: darwin
goarch: amd64
pkg: github.com/tikv/pd/server/schedule/placement
cpu: VirtualApple @ 2.50GHz
BenchmarkFitRegionWithMoreRulesAndStoreLabels-8              100           5371767 ns/op          356880 B/op      12879 allocs/op
PASS
ok      github.com/tikv/pd/server/schedule/placement    1.601s

master

➜  placement git:(master) ✗ go test -benchmem -run=^$ -bench ^BenchmarkFitRegionWithMoreRulesAndStoreLabels -benchtime=100x
goos: darwin
goarch: amd64
pkg: github.com/tikv/pd/server/schedule/placement
cpu: VirtualApple @ 2.50GHz
BenchmarkFitRegionWithMoreRulesAndStoreLabels-8              100          47968061 ns/op         2627010 B/op     107788 allocs/op
PASS
ok      github.com/tikv/pd/server/schedule/placement    5.801s

Release note

None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has not been approved.

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 submitting an approval review. Reviewer can cancel approval by submitting a request changes review.

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 75.81%. Comparing base (f5d4636) to head (2df2a09). :warning: Report is 1911 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5277      +/-   ##
==========================================
+ Coverage   75.70%   75.81%   +0.11%     
==========================================
  Files         311      311              
  Lines       30826    30835       +9     
==========================================
+ Hits        23338    23379      +41     
+ Misses       5485     5464      -21     
+ Partials     2003     1992      -11     

Flag	Coverage Δ
unittests	75.81% <100.00%> (+0.11%)	:arrow_up:

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

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

:rocket: New features to boost your workflow:

• :snowflake: Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[ti-chi-bot]

@AndreMouche: PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.