[Go Support] GoFrameworkAdapter base class

[KanishkThamman]

Expected Behavior

A GoFrameworkAdapter base class exists at
nuguard/sbom/adapters/go/_go_base.py that all Go framework adapters subclass,
providing Go-appropriate can_handle() semantics and shared helper methods —
analogous to TSFrameworkAdapter in
nuguard/sbom/adapters/typescript/_ts_regex.py.

Current Behavior

No Go adapter base class exists. If individual Go adapters were written without
a shared base, they would each re-implement can_handle() logic and helper
utilities, diverging from the Python/TypeScript pattern and making maintenance
harder.

Possible Solution

Create nuguard/sbom/adapters/go/_go_base.py:

1. Define GoFrameworkAdapter(FrameworkAdapter) — subclass of the shared
   FrameworkAdapter from nuguard/sbom/adapters/base.py. All shared
   fields (ComponentDetection, RelationshipHint, _framework_node(),
   priority, name) are inherited unchanged.
2. Override can_handle() to use substring/prefix matching against full Go
   module paths (e.g. "github.com/tmc/langchaingo" in mod), mirroring the
   substring matching that TSFrameworkAdapter.can_handle() uses for scoped
   npm packages.
3. Port the shared helpers from TSFrameworkAdapter (_resolve(), _clean(),
   _fw_node(), _template_vars()) so all Go adapters get the same toolkit
   without duplication.
4. extract() contract: receives GoParseResult as parse_result.

Steps to Reproduce (for bugs)

N/A — this is a feature addition.

Context

Part of #172 (Add Golang Support to NuGuard Pipeline).
Depends on sub-issues 1 and 2.
Blocking: all individual Go framework adapter sub-issues.