Add Integer#pack_* methods for uint* and int* types

[postmodern]

Add Integer#pack_* methods for all uint* and int* types for quickly packing Integers to common C types. These methods should pass the C type Symbol to pack along with **kwargs.

• Integer#pack_uint8
• Integer#pack_uint16
• Integer#pack_uint32
• Integer#pack_uint64
• Integer#pack_int8
• Integer#pack_int16
• Integer#pack_int32
• Integer#pack_int64

The following methods should not accept **kwargs as they use little-endian or big-endian:

• Integer#pack_uint8_le
• Integer#pack_uint16_le
• Integer#pack_uint32_le
• Integer#pack_uint64_le
• Integer#pack_int8_le
• Integer#pack_int16_le
• Integer#pack_int32_le
• Integer#pack_int64_le
• Integer#pack_uint8_be
• Integer#pack_uint16_be
• Integer#pack_uint32_be
• Integer#pack_uint64_be
• Integer#pack_int8_be
• Integer#pack_int16_be
• Integer#pack_int32_be
• Integer#pack_int64_be

Alias the *_be method to *_ne or *_net?

The documentation and specs can be copy/pasted from Integer#pack.

This will give ronin-support parity with pwnlib.util.packing.

[gfvcastro]

Hey @postmodern, I can work on it. Can you assign me this issue?

[postmodern]

An idea, Integer#pack_uint8 could probably be optimized to simply return self & 0xff.

[postmodern]

Did a Mastodon poll about _ne vs. _net suffix, and appears most people say to just use _be when referring to network-byte-order types. So maybe hold off on the _ne/_net aliases until someone eventually requests them?
https://infosec.exchange/@postmodern/110459088606261323