Change timer period to type of bigint in nanoseconds

[minggangw]

Per current implementation, the timer period is in milliseconds, because the range limitation of integer that JavaScript can represents. While, after BigInt introduced, we can change the timer period to type of bigint in nanoseconds, which aligns with other ROS2 clients, like rclpy.

This patch implements:

1. Change the timer period to type of bigint in nanoseconds for JavaScript side.
2. Get the period from v8::BigInt object as int64_t and pass it to rcl from C++ side.
3. Update the related unit tests accordingly.

Fix: #1037

[Copilot]

Copilot reviewed 27 out of 27 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (2)

test/test-msg-type-cpp-node.js:61

• The timer period value was changed from 100 (ms) to BigInt(100000) (ns), which implies a conversion factor of 1000. Please confirm that this conversion accurately reflects the intended timer duration now measured in nanoseconds.

var timer = node.createTimer(BigInt(100000), () => {

test/publisher_array_setup.js:42

• [nitpick] Different test files now use varying BigInt literal values (e.g. BigInt(100000) vs BigInt('100000000')). It would be beneficial to standardize the conversion factor from the previous millisecond values to nanoseconds to ensure consistent timer behavior across tests.

var timer = node.createTimer(BigInt('100000000'), () => {

[Copilot]

With the new bigint-based period in nanoseconds, the previous range validation (designed for millisecond values) has been removed. Consider adding a new range check that verifies the period is within acceptable nanosecond limits to avoid unintended timer values.

Suggested change

	const MIN_PERIOD = 1n; // 1 nanosecond
	const MAX_PERIOD = 3600000000000n; // 1 hour in nanoseconds