feat: add `extism-dev update --wasm` to update all the test wasm files across our repos

[zshipko]

Now extism-dev update --wasm can be used to update test wasm files across all our projects.

• Adds extraWasm field to data file to track additional test wasm files not found in extism/plugins repo
• Also adds some filters for extism-dev update: --category and --repo
• Adds --dry-run flag to see which files will be written before running
• Adds --build flag to update command to ensure kernel/test wasm modules are rebuilt before copying