feat: improve configuration of concurrent yurtappdaemon workers (#1912)

[huangchenzhao]

What type of PR is this?

/kind good-first-issue /kind feature

What this PR does / why we need it:

improve the configuration of concurrent yurtappdaemon workers in yurt-manager component

Which issue(s) this PR fixes:

Fixes #1912

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 52.32%. Comparing base (273e8df) to head (8103ec2).

Files	Patch %	Lines
...ntroller/yurtappdaemon/yurtappdaemon_controller.go	0.00%	3 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1981 +/- ## ========================================== - Coverage 52.38% 52.32% -0.07% ========================================== Files 174 174 Lines 20975 20973 -2 ========================================== - Hits 10988 10974 -14 - Misses 9039 9050 +11 - Partials 948 949 +1 ``` | [Flag](https://app.codecov.io/gh/openyurtio/openyurt/pull/1981/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openyurtio) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/openyurtio/openyurt/pull/1981/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openyurtio) | `52.32% <0.00%> (-0.07%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openyurtio#carryforward-flags-in-the-pull-request-comment) to find out more.

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[huangchenzhao]

/rerun

[rambohe-ch]

/lgtm