[feat] add controller concurrency options with elevated defaults

[eljohnson92]

What this PR does / why we need it:
Adds options to configure controller concurrency and QPS/Burst values to the kube API server
Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

TODOs:

• squashed commits
• includes documentation
• adds unit tests
• adds or updates e2e tests

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 39 lines in your changes missing coverage. Please review.

Project coverage is 66.06%. Comparing base (51681b7) to head (b670bdb).
Report is 1 commits behind head on main.

Files	Patch %	Lines
cmd/main.go	0.00%	31 Missing ⚠️
controller/linodecluster_controller.go	0.00%	2 Missing ⚠️
controller/linodemachine_controller.go	0.00%	2 Missing ⚠️
controller/linodeobjectstoragebucket_controller.go	0.00%	2 Missing ⚠️
controller/linodevpc_controller.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #407      +/-   ##
==========================================
- Coverage   66.58%   66.06%   -0.53%     
==========================================
  Files          42       42              
  Lines        2583     2620      +37     
==========================================
+ Hits         1720     1731      +11     
- Misses        768      794      +26     
  Partials       95       95              

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