_burn method from burn-internal doesn't adjust total supply

[leoloco]

Describe the bug

The internal method _burn from burn-internal.ts doesn't adjust total supply. The supply adjustment is done on burn.ts file. This is a bad practice because the burn method of burn.ts assumes that the caller's tokens are to be burned. However we shouldn't assume such a logic. It might be that some applications needs to burn from another account without allowance, i.e., perps, AMO stable coins, etc.