feat: bulk-edit the contacted station's gridsquare

An import that drops the locator leaves it missing on a whole batch, and fixing
that one QSO at a time is exactly what bulk edit exists to avoid.

Added on all three sides in lockstep — the dialog field, the field-to-column map,
and the repository whitelist — because they are separate lists and offering a
field the repository refuses fails only at Apply, after the operator has selected
the QSOs. The existing contract test covers it.

The callsign and RST stay excluded, as before: bulk-setting those corrupts a log.
The locator does not carry that risk — it identifies a place, not a station, and
a wrong value is simply overwritten again.

changelog.json

@@ -3,6 +3,7 @@
     "version": "0.21.9",
     "date": "2026-07-28",
     "en": [
+      "Bulk edit can now set the contacted station gridsquare, so a batch of QSOs imported without a locator can be corrected in one go.",
       "Filter builder: a confirmation date typed into a condition showed an empty box. The value was stored correctly, only the calendar field failed to display it.",
       "The Icom model list gains the IC-7300MKII (CI-V B6), plus the IC-7100, IC-7410, IC-7600 and IC-7851. The IC-7700 and IC-7800 were listed at the IC-7100's and IC-7410's addresses, so picking them set an address the rig never answers on.",
       "Icom over the LAN: the frequency no longer stays frozen after another program (WSJT-X through OmniRig, the Remote Utility) takes the CI-V session. The rig kept answering pings while sending nothing, so OpsLog showed the last known frequency until it was restarted; it now reconnects on its own.",
@@ -10,6 +11,7 @@
       "CQ and ITU zones you correct by hand in your profile stay corrected. They are derived from cty.dat, which gives the zones of the whole entity — in a country spanning several, the automatic value is wrong and it came back at every restart. They now only fill in when empty, and recompute when the callsign or grid changes."
     ],
     "fr": [
+      "L'édition groupée peut désormais définir le locator de la station contactée : un lot de QSO importés sans locator se corrige en une fois.",
       "Constructeur de filtres : une date de confirmation saisie dans une condition s'affichait dans une case vide. La valeur était bien enregistrée, seul le champ calendrier ne la montrait pas.",
       "La liste des modèles Icom gagne l'IC-7300MKII (CI-V B6), ainsi que les IC-7100, IC-7410, IC-7600 et IC-7851. Les IC-7700 et IC-7800 y figuraient avec les adresses des IC-7100 et IC-7410 : les choisir réglait une adresse sur laquelle la radio ne répond jamais.",
       "Icom via le réseau : la fréquence ne reste plus figée après qu'un autre programme (WSJT-X via OmniRig, la Remote Utility) a pris la session CI-V. La radio continuait de répondre aux pings sans rien émettre, si bien qu'OpsLog affichait la dernière fréquence connue jusqu'à son redémarrage ; il se reconnecte désormais tout seul.",