feat: add --maven flag to local source for loading from Maven ZIP artifacts

[jimisola]

Description

Extend the local source to accept Maven ZIP artifacts (with classifier reqstool) in addition to local directory paths.

Current behavior

reqstool report-asciidoc local --path /path/to/reqstool-data

Desired behavior

# Current: local directory
reqstool report-asciidoc local --path /path/to/reqstool-data

# New: Maven ZIP artifact
reqstool report-asciidoc local --maven /path/to/artifact-0.0.4-reqstool.zip

Same applies to generate-json and status commands.

Implementation notes

• Add --maven flag to local source parser (mutually exclusive with --path)
• Extract and validate ZIP structure
• Pass to LocationInterface for processing