e2e: test oras commands before 0.16.0

[qweeah]

Need to cover below ORAS commands

Manifest

• [ ] https://github.com/oras-project/oras/issues/586
• [ ] https://github.com/oras-project/oras/issues/585
• [ ] https://github.com/oras-project/oras/issues/565

Repository

• oras repository list: List repository
• oras repository show-tags: List tags of a repository

Blob

• [ ] https://github.com/oras-project/oras/issues/587
• [ ] https://github.com/oras-project/oras/issues/584
• [ ] https://github.com/oras-project/oras/issues/573

Tag

• oras tag $registry/$repository:<TAG|DIGEST> new_tag: Tag one manifest: Tag a manifest with single tag:
• oras tag $registry/$repository:original_tag [tag1[,tag2...]]: Tag a manifest with multiple tags

Tagging related

• oras push $registry/$repository[:TAG1[,TAG2 ...]] push multiple tags in one time
• oras copy $registry/$repository[:TAG1[,TAG2...]]: copy with multi-tagging

[yuehaoliang]

There's one more oras manifest fetch-config command. Just created it #588.