Footprints plugin: handle subsets/markers when linking by WCS (#3276)

* update alert language in orientation plugin
* footprints: if changing link type fails, redirect to orientation plugin - not ideal if the plugin is either inline or a popout... in the future we could detect whether there are subsets or markers and edit the text to say they will be removed (either in one button or additional buttons as-per the orientation plugin)

CHANGES.rst

@@ -89,6 +89,11 @@ Imviz
 
 - Remove "From File.." option when running on an external server. [#3239]
 
+- Button in the footprints plugin to change the link-type now redirects to the orientation plugin
+  when the change fails due to the presence of subsets or markers. [#3276]
+
+- Updates UI language in the orientation plugin to better match API. [#3276]
+
 Mosviz
 ^^^^^^
 

jdaviz/configs/imviz/plugins/footprints/footprints.py

@@ -197,7 +197,11 @@ def vue_link_by_wcs(self, *args):
         # call other plugin so that other options (wcs_fast_approximation, wcs_use_fallback)
         # are retained.  Remove this method if support for plotting footprints
         # when pixel-linked is reintroduced.
-        self.app._jdaviz_helper.plugins['Orientation'].align_by = 'WCS'
+        op = self.app._jdaviz_helper.plugins['Orientation']
+        if op._obj.need_clear_astrowidget_markers or op._obj.need_clear_subsets:
+            op.open_in_tray()
+        else:
+            op.align_by = 'WCS'
 
     def _ensure_first_overlay(self):
         if not len(self._overlays):

jdaviz/configs/imviz/plugins/orientation/orientation.vue

@@ -23,12 +23,20 @@
         </v-alert>
 
         <v-alert
-          v-if="wcs_linking_available"
+          v-if="wcs_linking_available && !need_clear_astrowidget_markers && !need_clear_subsets"
           type='warning'
           class="ignore-api-hints"
           style="margin-left: -12px; margin-right: -12px"
         >
-          Switching link type will reset zoom.
+          Switching alignment will reset zoom.
+        </v-alert>
+
+        <v-alert
+          v-if="plugin_markers_exist && !need_clear_astrowidget_markers && !need_clear_subsets"
+          type='warning'
+          style="margin-left: -12px; margin-right: -12px"
+        >
+          Marker positions may not be pixel-perfect when changing alignment/linking options.
         </v-alert>
 
         <v-alert v-if="need_clear_astrowidget_markers" type='warning' style="margin-left: -12px; margin-right: -12px">
@@ -38,12 +46,9 @@
           </v-row>
         </v-alert>
 
-        <v-alert v-if="plugin_markers_exist" type='warning' style="margin-left: -12px; margin-right: -12px">
-          Marker positions may not be pixel-perfect when changing alignment/linking options.
-        </v-alert>
 
         <v-alert v-if="need_clear_subsets" type='warning' style="margin-left: -12px; margin-right: -12px">
-          Existing subsets will be deleted on changing alignment/linking options.
+          Existing subsets must be deleted before changing alignment/linking options.
           <v-row justify="end" style="margin-right: 2px; margin-top: 16px">
             <v-btn @click="delete_subsets">
               {{ api_hints_enabled ?