feat: add java.sql.Time converter support

[SummerC0zyR0ck]

Purpose of the pull request

Related: #1017

Add first-class converter support for java.sql.Time, following the existing LocalTime converter pattern.

What's changed?

java.sql.Time represents a time-of-day value, but converter lookup uses the declared Java class. Therefore, the existing java.util.Date and LocalTime converters do not apply to fields declared as java.sql.Time.

This PR adds a converter family under org.apache.fesod.sheet.converters.sqltime:

• SqlTimeDateConverter - default write path using an Excel DATE cell. It attaches DateUtils.EPOCH (1970-01-01) and applies HH:mm:ss by default.
• SqlTimeNumberConverter - bidirectional Excel numeric serial conversion, including use1904windowing. Reading extracts the time component and discards any date component.
• SqlTimeStringConverter - bidirectional STRING conversion. It defaults to HH:mm:ss, auto-detects HH:mm input, and respects @DateTimeFormat and the configured Locale.

The converters reuse the existing LocalTime parsing, formatting, and Excel serial handling through Time.toLocalTime() and Time.valueOf(LocalTime). No time-zone conversion is introduced.

Registration in DefaultConverterLoader follows the LocalTime pattern:

• Number and String converters in initAllConverter()
• Date converter as the default write converter
• String converter for string-formatted writes

Tests

Tests cover converter keys, DATE/NUMBER/STRING conversion, custom date-time formats, 1904 date windowing, discarding the date component from numeric values, registry immutability, and round-trip behavior for XLSX, XLS, and CSV.

The complete fesod-sheet test suite passes with 923 tests, and both spotless:check and Apache RAT checks are green.

Scope is limited to java.sql.Time and remains JDK 8 compatible.

[bengbengbalabalabeng]

Since the converter respects the configured Locale, it would be great to include tests that verify locale‑specific formatting.

For example, "HH:mm:ss a" produces "AM/PM" under Locale.US, but "上午/下午" under Locale.CHINA.

[SummerC0zyR0ck]

Since the converter respects the configured Locale, it would be great to include tests that verify locale‑specific formatting.

For example, "HH:mm:ss a" produces "AM/PM" under Locale.US, but "上午/下午" under Locale.CHINA.

Thanks for the suggestion! I added a locale-specific formatting test covering Locale.US (PM) and Locale.CHINA (下午) with the HH:mm:ss a pattern. The test passes.

[bengbengbalabalabeng]

LGTM.

NOTE: This change will be merged after the current release is completed. We'll follow up and push the merge forward once the release is done.

[SummerC0zyR0ck]

LGTM.

NOTE: This change will be merged after the current release is completed. We'll follow up and push the merge forward once the release is done.

Thanks for the review and the LGTM! I understand the merge will wait until the current release is completed. I'll keep the branch rebased on main and am happy to resolve any conflicts if needed — just ping me when the release is done.