Do not use @types/dns-packet

The @types/dns-packet package does not provide enough benefit to be worth leaking its types to users of this package.

Split into CLI and library

install dohdec-cli if you want the dohdec CLI. dohdec is just the library now.

Bring up to date

Major

• Added padding for both JSON and DNS formats. All requests will be multiples of 128 bytes.
• Add HTTP/2 support by switching to got
• Added typescript types
• Switched to ES6 module format. This was a BREAKING change, which required a major version bump.
• Added reverse lookups when IP addresses are specified for a name.

Minor

• Removed large punycode dependency.
• Reworked verbose mode so a restart is no longer used. Verbosity is now an integer; you can specify "-v" multiple times to get more verbose from the command line.
• Made CLI testable.
• Mocked all network traffic (including DNS-over-TLS) for testing.

Housekeeping

• Updated dependencies.
• Switched to GitHub Actions from travis.
• master -> main
• Updated linting to match my other projects.