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.