Refactor Plugins into repeatable Class

[TheDr1ver]

Right now Shodan and Censys are just a collection of independent functions. This causes a lot of crappy logic in helper.py to the tune of if service == "censys-v2": iocs = censys.censys_v2_extract_certs(iocs, new_res).

Ideally each active plugin would be loaded as a generic, repeatable class, and we could just loop through all active plugins at each of these steps instead of explicitly looking for the slugs we know we've defined.

For example, censys.py does the following:

• Search for certificate data
• Clean JSON blobs
• Remove data from keys that is likely to be highly variable (timestamps, crawler IDs, etc)
• Extract certificates from JSON blob and add to IOCs
• Run a custom search against Censys
• Search Censys for IPs related to a specific certificate
• Get the details of a specific IP/host

shodan.py basically does the same exact stuff. This should pretty much always be the same for all plugins capable of generating misphunter-host objects.

• clean JSON blobs
• Remove data from keys that is likely to be highly variable (timestamps, crawler IDs, etc)
• Extract certificates from JSON blob and add to IOCs
• Run a custom search against Shodan
• Search Shodan for IPs related to a specific certificate
• Get the details of a specific IP/host