refactor: update duration parser to align with ISO 8601 standard

- Replaced naive parsing with structured component-based approach
- Enhanced both iso8601 and human-readable parsers with proper validation and unit order checks
- Added more tests, achieving 97.52% test coverage

Author: lemorage

docs/docs/core/data_types.mdx

@@ -35,7 +35,7 @@ This is the list of all basic types supported by CocoIndex:
 | Time | | `datetime.time` | `datetime.time` |
 | LocalDatetime | Date and time without timezone | `cocoindex.LocalDateTime` | `datetime.datetime` |
 | OffsetDatetime | Date and time with a timezone offset | `cocoindex.OffsetDateTime` | `datetime.datetime` |
-| TimeDelta | A duration of time | `cocoindex.typing.TimeDelta` | `datetime.timedelta` |
+| TimeDelta | A duration of time | `datetime.TimeDelta` | `datetime.timedelta` |
 | Vector[*T*, *Dim*?] | *T* must be basic type. *Dim* is a positive integer and optional. |`cocoindex.Vector[T]` or `cocoindex.Vector[T, Dim]` | `list[T]` | 
 | Json | | `cocoindex.Json` | Any data convertible to JSON by `json` package |