Implement format specifiers at log points, etc.

[zero-plusplus]

RELATED: #237 (comment)

I was looking for a format for converting variable values to hexadecimal, etc., for log points, etc., and format specifiers seems to be good and easy to implement.

The idea of converting the following objects to strings can also be implemented with this.

• Consider implementing a feature to output an object as a string #231

number := 123
; @Debug-Output => decimal: {number}
; @Debug-Output => hex: {number, X}

obj := { key: "value" }
; @Debug-Output => {obj, yaml}
; @Debug-Output => {obj, json}

[zero-plusplus]

The following specifiers are supported.

• b - binary (e.g. 123, b to "1111011")
• d - decimal (e.g. "0x123", d to 291)
• o - octal (e.g. 123, o to "173")
• x, h - hex (e.g. 123, x to "0x7b")
• X, H - hex (e.g. 123, X to "0x7B")
• xb, hb - hex (e.g. 123, xb to "7b")
• Xb, Hb- hex (e.g. 123, Xb to "7B")
• J - JSON string
• Jo - Oneline JSON string

If something is missing, please request it.