[Ephemeris] core implementation's getUrl() fails with windows path notations

[UdoKrie]

Expected Behavior

Calls to getBankHolidayName(ZonedDateTime, String) shall return.

Current Behavior

When the ephemeris binding calls this core function, an exception is thrown.
Working hypothesis is that getUrl() creates a malformed URL from the string passed, especially when windows paths are passed, starting with a drive letter, e.g. C:\.

Possible Solution

Change

            try {
                return new URL("file:" + filename);
            } catch (MalformedURLException e) {
                throw new FileNotFoundException(e.getMessage());
            }

to

            try {
                return filename.toURI().toURL();
            } catch (MalformedURLException e) {
                throw new FileNotFoundException(e.getMessage());
            }

Steps to Reproduce (for Bugs)

Discussions in thread https://community.openhab.org/t/ephemeris-custom-file-not-found/167428/4
0. have openHAB on Windows

1. Use ephemeris binding
2. create a custom thing
3. Apply an ephemeris XML file
4. See error message File is absent: ...

Context

Blocking for using custom ephemeris on windows installations

Your Environment

• Version used: V5.1.3
• Environment name and version openJDK 21
• Operating System and version Windows Server 2019 / Windows 10 / Windows 11