Emit warning on integer & floating-point overflow

[eemeli]

Very large and very small numbers cannot be exactly represented with a JS Number.

When parsing a YAML document with such values (e.g. 1e-400, 61e9540), we should emit a warning if we're representing them as a Number with lossy precision.

This would correspond to what we're already doing when parsing a mapping with a non-scalar key as an Object rather than a Map:

yaml/src/nodes/addPairToJSMap.ts

Lines 59 to 62 in 1dbf1c7

	warn(
	ctx.doc.options.logLevel,
	`Keys with collection values will be stringified due to JS Object restrictions: ${jsonStr}. Set mapAsMap: true to use object keys.`
	)