* Feat: replace custom har-validator with hard-validator-compiled package

* test(http-snippet): update casing

* fix: linting

Ensure that code snippets use enum members that are pascal cased and
not upper cased. For example use `Method.Get` instead of `Method.GET` to
ensure the snippets can compile.

fixes Kong#365

use `var` for return "type" of RestSharp request response

The type `IRestResponse` doesn't exist in latest client (version 112)

fixes Kong#367

* fix(form-data): override import from package root

* fix(httpsnippet): linting errors

…HAs (Kong#378)

* Pin all external github actions to their corresponding commit SHAs

* Update security actions to use the latest commit