Add `golangci-lint` configuration

[iamrajiv]

References:

https://golangci-lint.run/usage/configuration/

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[mgfeller]

Some configs from other repos:

• https://github.com/meshery/meshery/blob/master/.golangci.yml
• https://github.com/meshery/meshery-consul/blob/master/.golangci.yml
• https://github.com/meshery/meshery-operator/blob/master/.golangci.yml

[mgfeller]

@mgfeller Please specify the directories which has to be skipped in this configuration while running the golangci-lint.

.github I guess, possibly helpers (unless we suddenly get code there, not unlikely), otherwise I think all should be included.