refactor: use secret types in core v1 pkg

[adohe]

What type of PR is this?

What this PR does / why we need it:

use secret types in core v1 pkg

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Additional documentation e.g., design docs, usage docs, etc.:

[coveralls]

Pull Request Test Coverage Report for Build 7286879957

• 27 of 35 (77.14%) changed or added relevant lines in 5 files are covered.
• 8 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.08%) to 74.508%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/secrets/providers/azure/keyvault/keyvault.go	7	15	46.67%

Files with Coverage Reduction	New Missed Lines	%
pkg/engine/operation/watch.go	1	85.93%
pkg/cmd/destroy/options.go	7	82.13%

Totals
Change from base Build 7285874075:	-0.08%
Covered Lines:	7272
Relevant Lines:	9760

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💛 - Coveralls