feat: Add PR number to version string on PR builds (#1887)

* Add PR number to version string

* Testing another way

* Decide according to GitHub ref type how to parse and where to output.
Prioritize EDGETX_VERSION_TAG, if set, else resort to EDGETX_VERSION_SUFFIX, if set.
Adjust also firmware_version and boot_version strings and adjist bootloader title.

* Consider also B/W.

* B&W: omit GIT SHA if tagged, otherwise own line
Omit GIT SHA from version string if a tagged version.
Otherwise, show on own line since is too long for 128x64 B&W displays.

Co-authored-by: Peter Feerick <peter.feerick@gmail.com>

tools/build-gh.sh

@@ -48,14 +48,20 @@ fi
 
 : ${SRCDIR:=$(dirname "$(pwd)/$0")/..}
 
-gh_tag=${GITHUB_REF##*/}
-gh_branch=$(git rev-parse --abbrev-ref HEAD)
+gh_type=$(echo "$GITHUB_REF" | awk -F / '{print $2}') #heads|tags|pull
 
-if [[ -z $gh_tag ]];
-then
-  export EDGETX_VERSION_SUFFIX=$gh_branch
+if [[ $gh_type = "tags" ]]; then
+  # tags: refs/tags/<tag_name>
+  gh_tag=${GITHUB_REF##*/}
+  export EDGETX_VERSION_TAG=$gh_tag
+elif [[ $gh_type = "pull" ]]; then
+  # pull: refs/pull/<pr_number>/merge
+  gh_pull_number=PR$(echo "$GITHUB_REF" | awk -F / '{print $3}')
+  export EDGETX_VERSION_SUFFIX=$gh_pull_number
 else
-  export EDGETX_VERSION_SUFFIX=$gh_tag
+  # heads: refs/heads/<branch_name>
+  gh_branch=${GITHUB_REF##*/}
+  export EDGETX_VERSION_SUFFIX=$gh_branch
 fi
 
 : ${BUILD_TYPE:=Release}