refactor: use defined types

[knqyf263]

Description

The type of target is currently string such as "alpine", "python", "terraform", etc. It frequently leads to a bug due to type confusion. To prevent such mistakes, this PR introduces defined types for the target, and fixes found bugs thanks to the defined types.

Checklist

• I've read the guidelines for contributing to this repository.
• I've followed the conventions in the PR title.
• I've added tests that prove my fix is effective or that my feature works.
• I've updated the documentation with the relevant information (if needed).
• I've added usage information (if the PR introduces new options)
• I've included a "before" and "after" example to the description (if the PR is a user interface change).

[DmitriyLewen]

LGTM.
I have 1 question: Gomod analyzer should use analyzer.TypeGoMod, right?

trivy/pkg/fanal/analyzer/language/golang/mod/mod.go

Line 33 in 37af529

analyzer.RegisterPostAnalyzer(types.GoMod, newGoModAnalyzer)

[knqyf263]

@DmitriyLewen You're right. Can you please fix it? I'm away from a computer.

Also, this change was probably made by a linter (misspel?). Can we add an exception for auto-fix?
1954bd2

[DmitriyLewen]

You're right. Can you please fix it?

Changed in e1170d7

Can we add an exception for auto-fix?

Added licenCe word to ignore-words list for misspell linter in aad7837