Scroll support for WheelEvent.DOM_DELTA_PAGE

Is your feature request related to a problem? Please describe.

When the scroll is set to "One screen at a time" on Windows .
From personal observations (zooming in):

• On Chrome/Edge { deltaMode: 2, deltaY: -0.8 }
• On Firefox { deltaMode: 2, deltaY: -1 }

so currently, you zoom miniscule amount.

There are other findings, though some a bit outdated:

• https://github.com/w3c/pointerevents/issues/592#issuecomment-392648065 - Chrome and Edge behave the same on Windows.
• https://github.com/w3c/pointerevents/issues/592#issuecomment-2228196131 - attached google docs.

Normalization examples:

• https://github.com/facebookarchive/fixed-data-table/blob/master/src/vendor_upstream/dom/normalizeWheel.js

Describe the solution you'd like

It is not very clear how much a page scroll should be in zooming context. Suggestions:

• scaling delta like WheelEvent.DOM_DELTA_LINE with a presumptive const PAGE_SIZE = 8 * LINE_SIZE
• delta = Math.sign(delta) * this.deltaPerZoom_

Start by locating the map zoom handling for WheelEvent.DOM_DELTA_LINE and compare it with the reported Chrome, Edge, and Firefox DOM_DELTA_PAGE values. Review the linked normalization examples and determine a consistent page-size or zoom-step policy; done means page-mode wheel events produce an appropriate, tested zoom amount.