[stdlib] Simplified generic error code module. #252_150

[satyamacn]

Motivation

Introduces canonical errors as an option which apps may or may not follow. When a user defines an error reason, they may use the convention

// Message const ESOME_WRONG = 0xCCRRRR; Where CC is a byte with the category and RRRR two bytes with the reason.

[sahithiacn]

/canary

[bors-diem]

:sunny: Canary successful

[sahithiacn]

/land