feat(copy): makes copy more efficient

[leonardochaia]

What this PR does / why we need it

This PR improves CopyAsync and CopyGraphAsync to include the CopyOptions, inspired from oras-go.

The current implementation:

1. adds support for CopyOptions events, like OnPreCopy, these were implemented in the form of Action<T>s
2. adds support for mounting layers from other repositories.

Pending items

• Concurrency support
• Fix copy mounting tests
• Test CopyOptions events

Which issue(s) this PR resolves / fixes

Fixes #50

Please check the following list

• Does the affected code have corresponding tests, e.g. unit test, E2E test?
• Does this change require a documentation update?
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have an appropriate license header?

[leonardochaia]

This is a work in progress. Seems to be working running locally. Tests are failing and need more work.