Add a patch option to modify objects

[VimCommando]

Add a -p | --patch <JSON> option to add/override values in the output objects.

This could be useful on all commands:

1. bundle - all entries in the NDJSON have the patch
2. unbundle - all output files have the patch
3. merge - the singe output object has the patch
4. split - all the output files have the patch

Example use cases:

• Adding or modifying the updated_at or modified timestamps
• Incrementing object versions
• Adding a managed: true or similar value