Replace TS enums by plain objects

[arobsn]

TypeScript Enums are bad, consider replacing them by plain objects for improved compatibility and efficiency.

Plain object enum example:

export const ergoTreeHeaderFlags = {
  sizeInclusion: 0x08,
  constantSegregation: 0x10
} as const;

export type ErgoTreeHeaderFlag = (typeof ergoTreeHeaderFlags)[keyof typeof ergoTreeHeaderFlags];