Separate iv_prefix for GCM and CTR modes

[asfimport]

There is an ambiguity in what the iv_prefix applies to - GCM or CTR or both. This parameter will be moved it to the Algorithms structures (from the FileCryptoMetaData structure).

Reporter: Gidon Gershinsky / @ggershinsky
Assignee: Gidon Gershinsky / @ggershinsky

PRs and other links:

• GitHub Pull Request #2574
• GitHub Pull Request #496
• GitHub Pull Request #103
• PR

_{Note: This issue was originally created as PARQUET-1398. Please see the migration documentation for further details.}