Clarify cr version check statuses and add call to action (brave#25376)

Update statuses and step description to be clearer.

.github/workflows/compare-chromium-versions.yml

@@ -15,34 +15,34 @@ jobs:
       PR_NUMBER: ${{ github.event.pull_request.number }}
       PR_SHA: ${{ github.event.pull_request.head.sha }}
     steps:
-      - run: |
-          # Comparing Chromium versions between the PR branch and the target branch
+      - name: Check if CI and merge are allowed based on the Chromium version in the target branch
+        run: |
           shopt -s inherit_errexit
           set -eEo pipefail
 
           chromium_ver() { curl -fsS "https://raw.githubusercontent.com/${GITHUB_REPOSITORY:?}/${1:?}/package.json"|jq -r .config.projects.chrome.tag; }
 
           pr_ver="$(chromium_ver "${PR_SHA:?}")"
           target_ver="$(chromium_ver "${GITHUB_BASE_REF:?}")"
-          pfx="Target branch Chromium version"
 
-          status() { echo "::${1:?}::${2:?}"; echo "$2" >"${GITHUB_STEP_SUMMARY:?}"; }
+          status() { echo "::${1:?}::${2:?}"; echo "$2" >>"${GITHUB_STEP_SUMMARY:?}"; }
           label() { gh pr edit "${PR_NUMBER:?}" -R "${GITHUB_REPOSITORY:?}" "--${1:?}-label" chromium-version-mismatch >/dev/null; }
-          success() { status notice "${pfx:?} ${1:?}: CI ✅ | Merge ✅"; label remove; }
+          success() { status notice "${1:?}: CI ✅ | Merge ✅"; label remove; }
           failure() {
               case "${1:?}" in runci) ci=✅; label remove;; *) ci=🚫; label add;; esac
-              status error "${pfx:?} ${2:?}: CI $ci | Merge 🚫"
+              status error "${2:?}: CI $ci | Merge 🚫"
+              status error "Please rebase."
               exit 2
           }
 
           echo "::notice::PR branch: ${pr_ver:?}, target branch: ${target_ver:?}"
 
           if [[ "$pr_ver" == "$target_ver" ]]; then
-              success match
+              success "Chromium version full match"
           elif [[ "$(sort -V <<<"$target_ver"$'\n'"$pr_ver"|tail -n1)" == "$pr_ver" ]]; then
-              success older
+              success "Chromium version is newer in the PR"
           elif [[ "${pr_ver%%.*}" == "${target_ver%%.*}" ]]; then
-              failure runci "major match only"
+              failure runci "Chromium version partial match"
           else
-              failure blockci mismatch
+              failure blockci "Chromium version mismatch"
           fi