CI: Add automatic PR creation for source string updates (#4544)

* wording

* add pr creation

* Update translations.yml

* Update translations.yml

* update translation workflow

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* skip ci update

* skip ci update

* update conditions

* remove empty line

* typo

* tee test

* cleanup

* pass data between steps

* opt for step output over env variable

* remove space

* create script

* wording

* fix fork protection, re-add pr run

* updates

* Update translations.yml

* adjust for new source paths

* update comment

* wording

Co-authored-by: ebbit1q <ebbit1q@gmail.com>

* wording

* reorder

* reorder

* fix deprecation of set-output

* fix version

---------

Co-authored-by: ebbit1q <ebbit1q@gmail.com>

.ci/update_translations.sh

@@ -0,0 +1,56 @@
+#!/bin/bash
+
+# ci script to update translation files
+# usage:
+# $0 cockatrice/cockatrice_en@source.ts cockatrice/src common
+# or
+# FILE="cockatrice/cockatrice_en@source.ts"
+# DIRS="cockatrice/src common"
+# $0
+# note: directories can't contain spaces
+
+# check parameters
+if [[ ! $FILE ]]; then
+  FILE="$1"
+  shift
+fi
+if [[ ! $FILE ]]; then
+  echo "no output file selected" >&2
+  exit 2;
+fi
+if [[ ! $DIRS ]]; then
+  DIRS="$*"
+fi
+if [[ ! $DIRS ]]; then
+  echo "no source directories selected to translate" >&2
+  exit 2;
+fi
+if [[ ! -e $FILE ]]; then
+  echo "output file does not exist at: $FILE" >&2
+  exit 3;
+fi
+
+# print version
+if ! lupdate -version; then
+  echo "failed to run lupdate" >&2
+  exit 4;
+fi
+
+# run lupdate, duplicating the output in stderr and saving it
+# for convenience we ignore that $DIRS will be split on spaces 
+# shellcheck disable=SC2086
+if ! got="$(lupdate $DIRS -ts "$FILE" | tee /dev/stderr)"; then
+  echo "failed to update $FILE with $DIRS" >&2
+  exit 4;
+fi
+
+# trim output
+output="${got##*(}" # trim everything before last (
+output="${output%%)*}" # trim everything after first )
+if [[ $output == $got ]]; then
+  echo "could not parse generated output" >&2
+  exit 4;
+fi
+
+# write output to ci environment file
+echo "output=$output" >> $GITHUB_OUTPUT

.ci/update_translations_template.md

@@ -0,0 +1,11 @@
+Updated language source strings:
+- {{ .cockatrice_output }} (Cockatrice)
+- {{ .oracle_output }} (Oracle)
+
+<br>
+
+Last changes are based on commit {{ .commit }}.
+
+---
+*This PR is automatically generated and updated by the workflow at `.github/workflows/translations.yml`.*<br>
+*After merging, all changes to the source language are available for translation at [Transifex](https://www.transifex.com/projects/p/cockatrice/) shortly.*