fix: fix map by line time related bugs

[TomRytt]

Description

Fixes #902.

Fixes the following issues:

1. Single lines times stopped at 6PM
2. First lines were from 11PM the day before
3. The wrong time was used to filter the times (recorded at times instead of scheduled start time) - which resulted in issue 2.

Optimizations:

1. Optimized the useMemo to return an empty array if no positions passed the filter (typically when no line is chosen yet)
2. Switched to using a Set to ensure times can only appear in options once

screenshots

Taken at 22:58 (two minutes before the next bus is scheduled)

Taken at 23:00 (after the bus is scheduled)

[github-actions]

Preview: https://s3.amazonaws.com/noam-gaash.co.il/11941665224/open-bus/154/index.html
Preview Storybook: https://s3.amazonaws.com/noam-gaash.co.il/11941665224/open-bus/154/storybook/index.html
Test Report (if available): 'https://s3.amazonaws.com/noam-gaash.co.il/11941665224/open-bus/8bc99c6068ea82e8eb17828f339ab0f8bd67fd4c/test-results/index.html'

[NoamGaash]

Great, thank you very much.
Consider adding tests or adding an issue describing the test cases that would cover this bug to prevent future regressions

[NoamGaash]

The name does not reflect that the output of this method is the number of minutes since midnight. Would you consider renaming this method?
This is my suggestion, but feel free to implement anything you like.

Suggested change

	function convertTo24HourAndToNumber(time: string): number {
	function timestringToMinutes(time: string): number {