[YUNIKORN-2092] Remove spark-operator AppManager

[craigcondit]

What is this PR for?

Removes the spark-k8s-operator AppManager plugin, as well as all generated code necessary for its implementation. This simplifies the AppManager code, as only the general plugin remains (and will be refactored out later).

What type of PR is it?

• - Bug Fix
• - Improvement
• - Feature
• - Documentation
• - Hot Fix
• - Refactoring

Todos

• - Task

What is the Jira issue?

https://issues.apache.org/jira/browse/YUNIKORN-2092

How should this be tested?

Screenshots (if appropriate)

Questions:

• - The licenses files need update.
• - There is breaking changes for older versions.
• - It needs documentation.

[codecov]

Codecov Report

Merging #711 (15095ad) into master (b1e44a5) will decrease coverage by 0.01%.
Report is 1 commits behind head on master.
The diff coverage is n/a.

❗ Current head 15095ad differs from pull request most recent head e0bc38a. Consider uploading reports for the commit e0bc38a to get more accurate results

@@            Coverage Diff             @@
##           master     #711      +/-   ##
==========================================
- Coverage   71.64%   71.64%   -0.01%     
==========================================
  Files          50       50              
  Lines        7950     7948       -2     
==========================================
- Hits         5696     5694       -2     
  Misses       2056     2056              
  Partials      198      198              

Files	Coverage Δ
pkg/appmgmt/appmgmt.go	56.45% <ø> (-1.37%)	⬇️
pkg/log/logger.go	86.76% <ø> (ø)

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[craigcondit]

Rebased on latest master (merge conflict in yunikorn-rbac.yaml).

[pbacsko]

+1 LGTM

I'd like to as @wilfred-s to take a look at it too just to be sure.

[wilfred-s]

LGTM
just code removal, not functionality change for Spark jobs