PinBuilder has trouble centering some high-Unicode symbols

Sandcastle example: [I kinda-sorta made Character Map in Cesium](https://sandcastle.cesium.com/#c=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)

Browser: Chrome

Operating System: Win10

I'm trying to use symbols ("wingdings"?) as icons on PinBuilder pins, and sometimes the result looks a little off:


I'm not sure if this is the font, or Canvas, or the browser, or some combination of thereof -- and I don't know if Cesium can do anything about it -- but I thought I should at least check here. If it turns out that this is e.g. Chrome's fault, I'm happy to file an issue with them instead.

Reproduce the linked Sandcastle Character Map example in Chrome on Windows 10, focusing on the PinBuilder output for the affected high-Unicode symbols. Trace the PinBuilder entry point and compare centering across those symbols; done means determining whether Cesium can correct the offset or documenting that it is a browser or font limitation.

Written by the indexing model from the issue text.