feat: Emit OTel-aligned http.client attributes from the net integration

[timfish]

Stacked on top of #1415 (feat/vNext).

Aligns the ElectronNet outgoing-request span with the http.client spans that @sentry/node's fetch instrumentation emits, so that under span streaming Relay can infer the low-cardinality span name and the high-cardinality description from the same sentry-conventions rules.

What changed

src/main/integrations/net-breadcrumbs.ts:

• Name is now the sanitized URL — `${method} ${sanitizedUrl}` via getSanitizedUrlStringFromUrlObject (client spans don't branch the name; Relay derives both name and description from attributes).
• Attributes are now OTel-aligned: http.request.method, server.address, server.port, url.full, url.path, url.query, url.scheme (URLs/queries filtered for PII), replacing the bespoke url / http.method / type: 'net.request'.
• onlyIfParent now follows hasSpanStreamingEnabled(client), so the span is emitted without an active parent under span streaming — matching the node/browser fetch instrumentation. Correct for both traceLifecycle: 'stream' (default) and 'static'.
• The Electron-specific sentry.origin (auto.http.electron.net) is kept.

This mirrors @sentry/node's undici/fetch instrumentation, minus the origin and the socket-derived extras (network.peer.*, http.request.method_original) which aren't needed for name/description inference.

Scope

SDK side only (the emitting integration). The electron.* startup ops and forwarded renderer spans are untouched — the startup ops are already static low-cardinality, and renderer spans are owned by @sentry/browser. Verifying/adding the http.client rules lives in getsentry/sentry-conventions.