[network] Implement a smart cache size (Request in QGIS)

[qgis-bot]

Request for documentation

From pull request qgis/QGIS#58548
Author: @nirvn
QGIS version: 3.40

[network] Implement a smart cache size

PR Description:

Description

This PR improves QGIS' handling of its network disk cache by using a smart cache size logic that dynamically sizes based on the disk cache storage's available space. The logic is taken from Firefox (https://github.com/mozilla/gecko-dev/blob/e0a62f1391f7d58fab20418adc9310b23708a792/netwerk/cache2/CacheFileIOManager.cpp#L4307), and will results in most users getting a larger cache size.

The objective here is to insure that our default cache size insures we are as friendly as we can to servers hosting XYZ tiles, incl. but not limited to OpenStreetMap.

Users can disable the smart cache size logic in favor of a static cache size in the Options dialog. On that front, the spin box represents MBs instead of KiBs, because we're in 2024 :)

Commits tagged with [need-docs] or [FEATURE]