Remove @bentley/icons-generic from AppUI packages (backport #1153)

[mergify]

Changes

This PR resolves #798 by removing dependency on deprecated @bentley/icons-generic package.

Testing

N/A

---

This is an automatic backport of pull request #1153 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 594690c has failed:

On branch mergify/bp/release/5.0.x/pr-1153
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You are currently cherry-picking commit 594690caa.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   common/changes/@itwin/appui-react/remove-icons-generic_2024-12-11-15-42.json
	new file:   common/changes/@itwin/core-react/remove-icons-generic_2024-12-11-15-42.json
	new file:   common/changes/@itwin/imodel-components-react/remove-icons-generic_2024-12-11-15-42.json
	modified:   ui/appui-react/package.json
	new file:   ui/appui-react/src/appui-react/icons/snaps/SvgSnaps.tsx
	new file:   ui/appui-react/src/appui-react/icons/snaps/SvgSnapsBisector.tsx
	new file:   ui/appui-react/src/appui-react/icons/snaps/SvgSnapsCenter.tsx
	new file:   ui/appui-react/src/appui-react/icons/snaps/SvgSnapsIntersection.tsx
	new file:   ui/appui-react/src/appui-react/icons/snaps/SvgSnapsMidpoint.tsx
	new file:   ui/appui-react/src/appui-react/icons/snaps/SvgSnapsNearest.tsx
	new file:   ui/appui-react/src/appui-react/icons/snaps/SvgSnapsOrigin.tsx
	modified:   ui/appui-react/src/appui-react/layout/footer/snap-mode/Snap.scss
	modified:   ui/appui-react/src/appui-react/layout/footer/snap-mode/Snap.tsx
	modified:   ui/appui-react/src/test/layout/footer/snap-mode/Snap.test.tsx
	modified:   ui/appui-react/src/test/statusfields/SnapMode.test.tsx
	modified:   ui/core-react/package.json
	modified:   ui/imodel-components-react/package.json

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   common/config/rush/pnpm-lock.yaml
	both modified:   ui/appui-react/src/appui-react/statusfields/SnapMode.tsx

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally