Add jax_fingerprint plugin

[maskit]

This adds an experimental plugin jax_fingerprint. The basic functionality is the same as ja3_fingerprint and ja4_fingerprint, but the configuration is more flexible.

jax_fingerprint plugin supports multiple fingerprinting methods, JA4 and JA3. The code to generate fingerprint was copied from the existing plugins. It partially supports JA4H as well. I only implemented the JA4H_a and JA4H_b. JA4H_c and JA4H_d are filled with 0s.

All the outputs, HTTP headers and logging, are disabled by default. You can selectively enable them by specifying header names or a log file name. Also you can choose how the plugin deal with headers from clients. You can keep the original header intact, overwrite it, or append a new value.

A completely new feature is generating fingerprints only for specified server names (SNI). You can pass a list of server names. And of course you can set headers only on specified paths (remap rules) by setting up the plugin as a remap plugin.

The plugin can be used with either OpenSSL or BoringSSL (the existing ja3 plugin does not work with BoringSSL).

All the features are available regardless of fingerprinting methods.