Unfuddle CompactObject

[dranikpg]

Goals:

1. We use 16 bits for mask space in a key/value pair, but use only 6 different flags exclusively on either values or keys. Reduce mask size to one byte (in key) and free up one byte in value
   • maybe move all flags to value to remove one byte from expiry table key additionally
2. Reduce code complexity
   • Use different types for keys and values, inheriting both compact object, but hiding non-relevant functions and simiplifying logic
   • Review old string management code and simplify it
   • Review externally induced interface members (returning directly RObjWrapper, stream/sbf functions) that should be kept in familiy code and simplified

-> save ony byte per slot, have simpler object interface and hopefully a few hundred lines less code

Steps:

• Remove async delete flag usage (can be replaced by a function parameter...)
• Refactor small string
• Tidy up huffman code, encoding code_
• Remove GetFirstByte
• Remove raw access to RObjWrapper, remove unnecessary functions (InlineLen(), allows empty state, etc)
• Remove OBJ_ENCODING_INT and similar, its never used
• Move encoding to tagbyte_
• Change huffman_enc to is_key and rebase all other usage around it
• Use basic different types to catch sloppy type usage (there are cases), set is_key implicitily
• Move all flags to key object
• Review Free/SetMeta/Reset/etc functionality to be duplicate free