Add `String#unpack_uint*`, `String#unpack_int*`, `String#unpack_float*` methods

[postmodern]

String should have core-exts that can unpack the String as a single uint*,int*, or float* type. These methods should call unpack1 with a single C type argument (ex: :uint32) and **kwargs.

• [ ] String#unpack_uint8
• [ ] String#unpack_uint16
• [ ] String#unpack_uint32
• [ ] String#unpack_uint64
• [ ] String#unpack_int8
• [ ] String#unpack_int16
• [ ] String#unpack_int32
• [ ] String#unpack_int64
• [ ] String#unpack_float32
• [ ] String#unpack_float64
• [ ] String#unpack_pointer
• [ ] String#unpack_cstring

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

• [ ] String#unpack_uint16_le
• [ ] String#unpack_uint32_le
• [ ] String#unpack_uint64_le
• [ ] String#unpack_int8_le
• [ ] String#unpack_int16_le
• [ ] String#unpack_int32_le
• [ ] String#unpack_int64_le
• [ ] String#unpack_float32_le
• [ ] String#unpack_float64_le
• [ ] String#unpack_uint16_be
• [ ] String#unpack_uint32_be
• [ ] String#unpack_uint64_be
• [ ] String#unpack_int8_be
• [ ] String#unpack_int16_be
• [ ] String#unpack_int32_be
• [ ] String#unpack_int64_be
• [ ] String#unpack_float32_be
• [ ] String#unpack_float64_be

Alias *_be methods as *_ne or *_net?

The documentation and specs can be copy/pasted from String#unpack1.

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

[postmodern]

An idea, String#unpack_uint8 could be optimized to just return getbyte(0).

[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