fix: normalizePathSlashes should normalize multiple leading slashes

[artemmufazalov]

Multiple slashed could be if we run multi-cluster mode in dev.

.env:

REACT_APP_BACKEND=
REACT_APP_META_BACKEND=http://ui-dev-0.ydb.yandex.net/api/meta8780
META_YDB_BACKEND=

CI Results

Test Status: ⚠️ FLAKY

📊 Full Report

Total	Passed	Failed	Flaky	Skipped
318	317	0	1	0

😟 No changes in tests. 😕

Bundle Size: ✅

Current: 83.36 MB | Main: 83.36 MB
Diff: +0.09 KB (0.00%)

✅ Bundle size unchanged.

ℹ️ CI Information

• Test recordings for failed tests are available in the full report.
• Bundle size is measured for the entire 'dist' directory.
• 📊 indicates links to detailed reports.
• 🔺 indicates increase, 🔽 decrease, and ✅ no change in bundle size.

[Copilot]

Pull Request Overview

This PR fixes the behavior of normalizePathSlashes to correctly normalize multiple leading slashes while preserving protocol double slashes.

• Updated the regex in normalizePathSlashes to use a negative lookbehind to ignore protocol specifiers.
• Added additional tests to verify behavior for both leading and protocol-based slashes.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/utils/index.ts	Updated regex in normalizePathSlashes and added an explanatory comment.
src/utils/test/index.test.ts	Added test cases for multiple leading slashes and for ensuring protocol slashes remain unchanged.

Comments suppressed due to low confidence (1)

src/utils/test/index.test.ts:32

• There's a typo in the test description; 'shoudl' should be corrected to 'should'.

test('shoudl not replace double slashes near protocols (after a colon)'...