feat: normalise datetime filters for non utc timezones

[Promist-Moon]

Description

This PR closes #4983. This PR adds end-to-end coverage for the timezone handling bug in History filters, where URL datetime values (e.g. 2026-07-22T10:05) filtered out workflows only in UTC timezones.

Changes made:

1. Filters in Workflow History filter out workflows by the browser's local timezone, detected by the browser's websocket offset minutes, both from editing the URL directly in the URL bar and through the page's filters

Validation

Go to the History tab.

Workflow run at 3:10PM UTC+8 (7:10AM in GMT) is filtered out when the filter 3:51PM is applied.

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