feat: add LNURL verify

[im-adithya]

Description

Fixes #2

• Adds LNURL verify at /lnurlp/:username/verify/:payment_hash
• The callback URL is shifted from /.well-known/lnurlp/:username/callback to /lnurlp/:username/callback
• Context type is added to avoid ts errors
• DEBUG is capitalized as LevelName type is defined as type LevelName = "NOTSET" | "DEBUG" | "INFO" | "WARN" | "ERROR" | "CRITICAL"

[bumi]

lgtm

[rolznz]

Nice branch name 😆

utACK