Implement ELF Symbol Download and Resolution

[brianrob]

Universal traces can currently be captured on Windows and Linux by one-collect. In order to provide first class support for analyzing these traces, PerfView/TraceEvent should suport ELF symbol download and resolution.

Tasks:

• Implement C++ symbol de-mangling.
• Implement Rust symbol de-mangling.
• Implement ELF symbol file parsing.
• Implement storage for ELF symbol metadata in TraceLog.
• Implement SymbolReader download support.

[brianrob]

cc: @zachcmadsen