Saved map resolutions and aligned with custom resolutions and projection of map

[subashtiwari1010]

Description

This PR reapplies the reverted fix from #11821, which prevents map freezes and OOM errors when the CRS changes while saved resolutions still belong to another projection. It also moves custom resolutions to per-CRS configuration in CRSSelector, so the CRS and its resolutions stay aligned when switching projections and when saving the map.

Changes

• Custom Resolutions: Can define resolution lists per SRS in localConfig.json; the plugin exposes them to the map on load and when the user changes CRS.
• Map save/load: When the CRS changes, then the map resolutions are updated and saved in the map options, so it is saved for current projections and when loading the map it is taken from saved information; regarding the custom resolutions, it is taken from plugin config when needed.
• Migration guide: Documents moving resolutions out of new.json into CRSSelector.

Please check if the PR fulfills these requirements

• The commit message follows our guidelines: https://github.com/geosolutions-it/MapStore2/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x", remove the others)

• Bugfix

Issue

What is the current behavior?
The OOM behavior happens if the resolutions and projection are provided in new.json file and user switch to different projection rather than the resolutions one.

#11779 (comment)

What is the new behavior?
When you change the map CRS, the custom resolutions configured for that CRS in CRSSelector is applied (or computes them if it is not set) and saves them with the map so they stay aligned on reload.

Breaking change

Does this PR introduce a breaking change? (check one with "x", remove the other)

• Yes, and I documented them in migration notes
• No

Other useful information