Merge remote-tracking branch 'upstream/master' into fixlookupfulltext

# By Tobias Diez (109) and others
# Via GitHub (109) and others
* upstream/master: (404 commits)
  set jabrefHost.py executable (#5530)
  Add CHANGELOG entry for #5482
  Fix text colour in Merge dialogue (#5521)
  Remove empty customization warning
  Fix typos in external-libraries.txt file
  Fix new entry serialization test
  Add test for alphabetic serialization of fields in BibEntry
  Fix XMP null error
  Bring back the scrollbars (#5515)
  Fix metadata serialization order (#5514)
  New ADS Fetcher (#5501)
  snap: Add browser proxy for confined browser integration (#5512)
  Fix dark theme loading
  Update PreviewViewer.java
  [WIP] Try to fix dark theme path
  Use Platform.runLater
  Fixes #5485
  Bump com.github.ben-manes.versions from 0.26.0 to 0.27.0
  Bump src/main/resources/csl-styles from `68a697b` to `c3fd4bd`
  Bump byte-buddy-parent from 1.10.1 to 1.10.2
  ...

# Conflicts:
#	src/main/resources/l10n/JabRef_en.properties

src/main/resources/l10n/JabRef_en.properties

@@ -2084,3 +2084,44 @@ Import\ new\ entries=Import new entries
 Group\ color=Group color
 
 Full\ text\ document\ found\ already\ on\ disk\ for\ entry\ %0.\ Not\ downloaded\ again.=Full text document found already on disk for entry %0. Not downloaded again.
+
+Columns=Columns
+File\ type=File type
+IEEE=IEEE
+Internal=Internal
+Special=Special
+Remove\ column=Remove column
+Add\ custom\ column=Add custom column
+Update\ to\ current\ column\ order=Update to current column order
+Sort\ column\ one\ step\ upwards=Sort column one step upwards
+Sort\ column\ one\ step\ downwards=Sort column one step downwards
+Synchronize\ special\ fields\ to\ keywords=Synchronize special fields to keywords
+Serialize\ special\ fields=Serialize special fields
+List\ must\ not\ be\ empty.=List must not be empty.
+
+Add\ field\ to\ filter\ list=Add field to filter list
+Add\ formatter\ to\ list=Add formatter to list
+Filter\ List=Filter List
+New\ column=New column
+Open\ files...=Open files...
+
+Affected\ fields\:=Affected fields:
+Show\ preview\ as\ a\ tab\ in\ entry\ editor=Show preview as a tab in entry editor
+Font=Font
+Visual\ theme=Visual theme
+Light\ theme=Light theme
+Dark\ theme=Dark theme
+Overwrite\ existing\ keys=Overwrite existing keys
+Key\ patterns=Key patterns
+Size\:=Size:
+Font\ settings=Font settings
+Override\ font\ settings=Override font settings
+Override\ font\ size=Override font size
+Theme\ changed\:=Theme changed\:
+You\ must\ enter\ an\ integer\ value\ higher\ than\ 8.=You must enter an integer value higher than 8.
+Letters\ after\ duplicate\ generated\ keys=Letters after duplicate generated keys
+Start\ on\ second\ duplicate\ key\ with\ letter\ A\ (a,\ b,\ ...)=Start on second duplicate key with letter A (a, b, ...)
+Start\ on\ second\ duplicate\ key\ with\ letter\ B\ (b,\ c,\ ...)=Start on second duplicate key with letter B (b, c, ...)
+Always\ add\ letter\ (a,\ b,\ ...)\ to\ generated\ keys=Always add letter (a, b, ...) to generated keys
+Default\ pattern=Default pattern
+Reset\ %s\ to\ default\ value=Reset %s to default value