Suppress StackParser to extract source code from files during tests

[Reversean]

Catcher read backtrace from file file via StackParser.

In most test-cases we don't have this file, still StackParser tries to find it, fails and output spam logs:

[@hawk.so/javascript]: Hawk JS SDK: Can not extract source code. Please, report this issue: https://github.com/codex-team/hawk.javascript/issues/new TypeError: fetch failed
[@hawk.so/javascript]:     at node:internal/deps/undici/undici:15845:13
[@hawk.so/javascript]:     at window.fetch (/home/reversean/Dev/codex/hawk.javascript/packages/javascript/src/addons/breadcrumbs.ts:398:20) {
[@hawk.so/javascript]:   [cause]: Error: not implemented... yet...
[@hawk.so/javascript]:       at makeNetworkError (node:internal/deps/undici/undici:10147:35)
[@hawk.so/javascript]:       at schemeFetch (node:internal/deps/undici/undici:11685:34)
[@hawk.so/javascript]:       at mainFetch (node:internal/deps/undici/undici:11533:30)
[@hawk.so/javascript]:       at fetching (node:internal/deps/undici/undici:11502:7)
[@hawk.so/javascript]:       at fetch (node:internal/deps/undici/undici:11368:20)
[@hawk.so/javascript]:       at fetch (node:internal/deps/undici/undici:15843:10)
[@hawk.so/javascript]:       at fetch (node:internal/bootstrap/web/exposed-window-or-worker:83:12)
[@hawk.so/javascript]:       at window.fetch (/home/reversean/Dev/codex/hawk.javascript/packages/javascript/src/addons/breadcrumbs.ts:398:26)
[@hawk.so/javascript]:       at fetchTimer (/home/reversean/Dev/codex/hawk.javascript/packages/core/src/modules/fetch-timer.ts:19:24)
[@hawk.so/javascript]:       at StackParser.loadSourceFile (/home/reversean/Dev/codex/hawk.javascript/packages/core/src/modules/stack-parser.ts:133:41)
[@hawk.so/javascript]: }

Suggested changes mocks StackParser.parse in catcher tests which prevents trash unwanted logs.

[neSpecc]

Debug if extractSourceCode is still working.

[Reversean]

Debug if extractSourceCode is still working.

Checked on packages/sveltekit/playground, http://localhost:4173/errors/runtime-error .

Launched in preview mode (bundled js).

For 11/12 stacktrace frames it returns null (including playground code), but managed to parse one frame, and apparently these fragments are SvelteKit bootstrap, so the final result looks like thrash

UPD

Anyway, on build (unbundled) it looks ok

[neSpecc]

Solution is ok, but we still need to find out if loadSourceFile is needed. And remove it if not.