[feature] Switch API server to huma for OpenAPI docs auto generation/documentation

[els0r]

Simplifies the API documentation massively, as it is now embedded in the struct tags. Closes #309 .

API

Under the hood, the huma framework is used:

• documents API via struct tags in relevant entities
• replaces route registration from the gin framework

Not only does this simplify the hooks into the API, it also doesn't touch the remaining server setup fundamentally. The router in front of huma is still gin.

The API documentation is reachable under the /docs endpoint.

Error Handling

This addresses parts of #277. The detail errors for parsing args now relies on the huma.ErrorModel, which returns an RFC-compliant list of errors.

The benefit is that every field in the query args is validated and the whole list of offending fields is returned in the error. Both the API and goQuery use this to provide details to the caller.

For goQuery, the output looks as follows

$ go run cmd/goQuery/main.go -i eth0 sip,dap -c "dport 89" -n 0
Error running query: failed to prepare query:

    query (value: sip,dap)
    ----------------------
    invalid query type: 
    
    sip,dap
        ^
    unknown attribute
    
    condition (value: dport 89)
    ---------------------------
    invalid condition: 
    
    dport 89
          ^
    expected comparison operator
    
    num_results (value: 0)
    ----------------------
    invalid number of result rows: must be > 0

Flags / OpenAPI Generation

The OpenAPI spec can now be generated by the tool itself. This is necessary in order to guarantee up-to-date generation during the release step.

To this end, the --openapi flag was added to both goProbe and global-query. It causes the tools to start and generate the API spec as soon as possible.

Since neither tools start without config, the .buildconfig directory contains a minimal, stripped-down config, which can be relied on for OpenAPI spec generation.

[fako1024]

Noice - Thanks for going through all the painful effort of documenting the stuff in code! There's a few minor points of feedback (and the usual nitpicks), but apart from that LGTM!