[feature] add AS information lookup

[digizeph]

Consider implement the following features

• search by name
• search by ASN
• order by AS sizes if multiple ASes match

Returning fields:

• ASN
• AS name
• Country code

bgp.tools whois table formatting look great:

Data sources:

• CAIDA AS Rank: https://api.asrank.caida.org/v2/docs
• bgp.tools: https://bgp.tools/kb/api
• (maybe) bgp.he.net: https://bgp.he.net/

[digizeph]

To ensure this tool works offline, we should preload the raw data and store it into a configured data folder with SQLite database as the storage backend.

• config file mechanism to specify data location (relevant PR: #9)
• bootstrap data into sqlite #10

[digizeph]

Resolved in #10