Allow eBPF map sizes and general buffer size for profiler to be changed via CLI options

[gmarler]

This PR adds several CLI options to set defaults for and allow modifying the size of most eBPF maps and the perf buffer for the profiler:

• --mapsize-info prints the eBPF map sizes after they've been created
• --mapsize-stacks to adjust max number of individual stacks to capture before they are aggregated
• --mapsize-aggregated-stacks to adjust the max number of unique stacks to be stored after aggregation from the stacks map
• --mapsize-unwind-info-chunks to adjust the max number of chunks allowed to be in a single shard
• --mapsize-unwind-tables to adjust the max number of shards allowed
• --mapsize-rate-limits to adjust when to impose rate limits on incoming profiling data
• --perf-buffer-bytes to adjust the size of each profiler perf buffer

Also added a config validator for --perf-buffer-bytes, as the value must be a power of 2.

Added tests for the validator function.

[javierhonduco]

LGTM, just left a comment about the value_is_power_of_two separation, if you could do it I think it would be nicer!