Added performance enhancements for various functions

This PR fixes the following clang-tidy warnings, though may fix many others as well as changes are pushed:

Variables are copy-constructed from a const reference but are only used as const references; consider making them const reference
'rfind' called with a string literal consisting of a single character; consider using the more effective overload accepting a character
string concatenation results in allocation of unnecessary temporary strings; consider using 'operator+=' or 'string::append()' instead
integer to pointer cast pessimizes optimization opportunities
parameters are passed by value and only copied once; consider moving them to avoid unnecessary copies
Parameters are copied for each invocation but only used as a const reference; consider making them const references

Additionally, this rewrites the compression routines to use Poco's InflationInputStream and DeflationInputStream classes.

samtupy / nvgt