Fix issues with reloading and handling of externally modified db file (#10612)

Fixes #5290 
Fixes #9062
Fixes #8545 

* Fix data loss on failed reload

- External modifications to the db file can no longer be missed.
- Fixed dialogFinished signal of DatabaseOpenDialog was not emitted when dialog was closed via the 'X' (close) button
- For reloading with a modified db, an additional choice has been added to allow the user to ignore the changes in the file on disk.
- User is now presented with an unlock database dialog if reload fails to open the db automatically. For example when the user removed the YubiKey, failed to touch the YubiKey within the timeout period, or db pw has been changed.
- Mark db as modified when db file is gone or invalid.
- Prevent saving when db is being reloaded
- If merge is triggered by a save action, continue on with the save action after the user makes their choice

---------

Co-authored-by: vuurvlieg <vuurvli3g@protonmail.com>
Co-authored-by: Jonathan White <support@dmapps.us>

share/translations/keepassxc_en.ts

@@ -1513,6 +1513,10 @@ Backup database located at %2</source>
         <source>Recycle Bin</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Database file read error.</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>DatabaseOpenDialog</name>
@@ -2683,24 +2687,6 @@ Save changes?</source>
         <source>File has changed</source>
         <translation type="unfinished"></translation>
     </message>
-    <message>
-        <source>The database file has changed. Do you want to load the changes?</source>
-        <translation type="unfinished"></translation>
-    </message>
-    <message>
-        <source>Merge Request</source>
-        <translation type="unfinished"></translation>
-    </message>
-    <message>
-        <source>The database file has changed and you have unsaved changes.
-Do you want to merge your changes?</source>
-        <translation type="unfinished"></translation>
-    </message>
-    <message>
-        <source>Could not open the new database file while attempting to autoreload.
-Error: %1</source>
-        <translation type="unfinished"></translation>
-    </message>
     <message>
         <source>Disable safe saves?</source>
         <translation type="unfinished"></translation>
@@ -2787,6 +2773,50 @@ Disable safe saves and try again?</source>
         <source>Do you want to remove the passkey from this entry?</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>The database file &quot;%1&quot; was modified externally</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Do you want to load the changes?</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Reload database</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Reloading database…</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Reload canceled</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Reload successful</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Reload pending user action…</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>The database file &quot;%1&quot; was modified externally.&lt;br&gt;How would you like to proceed?&lt;br&gt;&lt;br&gt;Merge all changes&lt;br&gt;Ignore the changes on disk until save&lt;br&gt;Discard unsaved changes</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>The database file &quot;%1&quot; was modified externally.&lt;br&gt;How would you like to proceed?&lt;br&gt;&lt;br&gt;Merge all changes then save&lt;br&gt;Overwrite the changes on disk&lt;br&gt;Discard unsaved changes</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Database file overwritten.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Database file on disk cannot be unlocked with current credentials.&lt;br&gt;Enter new credentials and/or present hardware key to continue.</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>EditEntryWidget</name>