chore: start using plugin-framework package

[priteshbandi]

chore: start using plugin-framework package.

#372 supersedes this PR (which I have converted to draft)

Note: this PR has breaking changes but they are required in order to add support for plugin as library.

This PR depends on notaryproject/notation-plugin-framework-go#5

[shizhMSFT]

Please consider starting moving to plugin framework package only after it reaches a stable version (i.e. v1.0.0).

[shizhMSFT]

We shall not remove any interfaces, types, or functions as notation-go is stable at v1.

Instead, consider this

type GenericPlugin = pluginframework.GenericPlugin

If the breaking change is not avoidable, you might need to consider notation-go/v2 but it would be another proposal to be discussed.

[shizhMSFT]

The same technique is applied when golang introduce the io/fs package as well as deprecate io/ioutil.

Examples can be found at https://pkg.go.dev/os#FileInfo

type FileInfo = fs.FileInfo

[priteshbandi]

I can try to add backward comparability support for interfaces but for other types and functions there would be breaking change. IMO the maintenance effort and code-change required to maintain backward comparability is not be worth it.
Lets discuss this in next community meeting, as suggested by you one way is to notation-go/v2

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Please consider starting moving to plugin framework package only after it reaches a stable version (i.e. v1.0.0).

I was thinking of doing v1 for plugin framework package at the same time when we do next release for notation-go.

[priteshbandi]

#372 supersedes this PR