search: remove zip file restriction for structural search

Created by: rvantonder

Searcher uses zip archives to search over file contents. It's not currently possible to perform structural search over large zips (containing >65K files or is larger than 4GB). The limitation stems from the fact that the zip library used by comby does not support ZIP64 format. To remove this restriction we either need to:

• Support ZIP64 in comby
• Use a different abstraction/format to search file contents (e.g., unix file system)