Rework socket storage module

[gfieni]

PR overview:

• Fixes various resources (memory, file descriptor) leaks ;
• Supports the connection to IPv6 endpoints ;
• Uses getrandom interface instead of srand which triggers static analysis warnings ;
• Remove static analysis exception about srand usage ;
• Simplify the socket connect/reconnect code paths ;
• Improves socket errors handling and logging ;
• Removes SIGPIPE ignore in main ;
• Removes srand initialisation in main ;
• Fixes static analysis warnings about unused code and dangerous functions.