fix: add diagnostic severity info to skaffold lint rules

[aaron-prindle]

Adds diagnostic severity info the skaffold lint rules that skaffold lint emits. This is passed onto the skaffold lsp to be displayed correctly in an IDE. Currently all of the lint rules are at Warning level which is yellow in the IDE. There are the following severity types (from - https://microsoft.github.io/language-server-protocol/specifications/specification-3-17/#diagnosticSeverity):

• Error (red underline, shows up in Problems section)
• Warning (yellow underline, maybe shows up in Problems section?)
• Info (blue underline)
• Hint (subtle ellipses underline at the beginning area)

[codecov]

Codecov Report

Merging #6862 (4e9dd75) into main (290280e) will decrease coverage by 1.34%.
The diff coverage is 61.83%.

@@            Coverage Diff             @@
##             main    #6862      +/-   ##
==========================================
- Coverage   70.48%   69.13%   -1.35%     
==========================================
  Files         515      547      +32     
  Lines       23150    25078    +1928     
==========================================
+ Hits        16317    17338    +1021     
- Misses       5776     6576     +800     
- Partials     1057     1164     +107     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/deploy.go	52.00% <ø> (-1.85%)	⬇️
cmd/skaffold/app/cmd/dev.go	84.61% <0.00%> (ø)
cmd/skaffold/app/cmd/flags.go	91.00% <0.00%> (+0.18%)	⬆️
cmd/skaffold/app/cmd/render.go	36.66% <0.00%> (-4.72%)	⬇️
cmd/skaffold/skaffold.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/inspect_tests.go	62.50% <14.28%> (-1.14%)	⬇️
cmd/skaffold/app/cmd/fix.go	68.85% <40.00%> (-7.62%)	⬇️
cmd/skaffold/app/cmd/lint.go	42.85% <42.85%> (ø)
cmd/skaffold/app/cmd/find_configs.go	48.88% <50.00%> (+0.24%)	⬆️
cmd/skaffold/app/skaffold.go	76.19% <70.00%> (-8.43%)	⬇️
... and 162 more

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[gsquared94]

lgtm