backport: keep PoSe score visible when hiding banned masternodes

[thepastaclaw]

Issue being fixed or feature implemented

The Hide banned checkbox on the Masternodes tab filters PoSe-banned
masternodes, but v23.1.x also hides the entire PoSe Score column. This prevents
users from seeing residual PoSe penalties on masternodes that are not yet
banned.

This was reported in #7286 and fixed on develop by
#7298. The fix has not reached the v23.1.x release branch.

What was done?

Backport the merged one-line fix from #7298. The checkbox continues
to filter banned rows through MasternodeListSortFilterProxyModel, while the
PoSe Score column remains visible.

How Has This Been Tested?

• Confirmed the v23.1.x handler explicitly hides the PoSe column when the
  checkbox is selected.
• Confirmed the banned-row filter remains independently enforced by the proxy
  model after removing the column-visibility call.
• Verified the backport patch is byte-for-byte identical to the merged fix.
• git diff --check
• Mandatory local pre-PR review: ship

A full GUI build was not run locally; GitHub CI will provide the branch build
coverage.

Breaking Changes

None.

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation
• I have assigned this pull request to a milestone (for repository code-owners and collaborators only)

[PastaPastaPasta]

Closing; I've added the backport label to the other PR, so it'll be included in next release.