fix: source property-functions where fn-plugin-property-* helpers are used

The release_and_deploy function and several proxy plugin scripts call fn-plugin-property-* helpers without sourcing `plugins/common/property-functions`, producing `command not found` errors during deploys. Source the helpers from `plugins/common/functions` and from each proxy plugin entry point that consumes them.

plugins/common/functions

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 set -eo pipefail
 [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/property-functions"
 
 has_tty() {
   declare desc="return 0 if we have a tty"
@@ -975,10 +976,6 @@ fn-migrate-config-to-property() {
     source "$PLUGIN_AVAILABLE_PATH/config/functions"
   fi
 
-  if ! declare -f -F fn-plugin-property-write >/dev/null; then
-    source "$PLUGIN_CORE_AVAILABLE_PATH/common/property-functions"
-  fi
-
   if [[ -n "$GLOBAL_CONFIG_VAR" ]]; then
     local value=$(plugn trigger config-get-global "$GLOBAL_CONFIG_VAR" || true)
     if [[ -n "$value" ]]; then