Adding optional arg to BF.INSERT to allow users to check if their bloom filter can reach the desired size

[zackcam]

DRAFT

Need to go over error messages
Need to change how we calculate capacity

Changes

Adding ATLEASTCAPCITY as an optional arg of BF.INSERT. New bf.insert command will look like:
BF.INSERT <key> [CAPACITY capacity] [ERROR fp_error] [EXPANSION expansion] [NOCREATE] [NONSCALING] [ATLEASTCAPACITY wantedcapacity] [ITEMS item]
This argument will help a user know whether the command will fail - at the time of creation if they want to expand their filter to a certain size.
There are two new error messages associated with this:

pub const WANTED_CAPACITY_EXCEEDS_MAX_SIZE: &str =
    "ERR Wanted capacity would go beyond bloom object memory limit";
pub const WANTED_CAPACITY_FALSE_POSITIVE_INVALID: &str =
    "ERR False positive degrades too much to reach wanted capacity";

Added checks for these two error messages in test_bloom_command.py