[#659] Cleveland Lorentz functions to import/embed values

Description

Problem: In Test.Cleveland.Lorentz.Import we have some utility functions that adapt some functions from Test.Cleveland.Michelson.Import to Lorentz sensibilities (types). However, an equivalent for importValue is missing. Furthermore, equivalents for embedContract and embedContractM for Values could be useful as well.

Solution: Implement importValue, embedValue and embedValueM.

This commit also tweaks embedContract and embedContractM documentation to mention some quirks (which apply to all Test.Cleveland.Lorentz.Import.embed* functions)

Related issue(s)

Resolves #659 (closed)

✅ Checklist for your Merge Request

Related changes (conditional)

• Tests (see short guidelines)

  • If I added new functionality, I added tests covering it.
  • If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.

• Documentation

  • I checked whether I should update the docs and did so if necessary:
    • Root README and other README.md files
    • Haddock
    • docs/
  • I updated changelog files of all affected packages released to Hackage if my changes are externally visible.

N/A, Cleveland is not released.

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