chore(rename): move llama_stack.distribution to llama_stack.core (#2975)

We would like to rename the term `template` to `distribution`. To
prepare for that, this is a precursor.

cc @leseb

llama_stack/core/common.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+cleanup() {
+  envname="$1"
+
+  set +x
+  echo "Cleaning up..."
+  conda deactivate
+  conda env remove --name "$envname" -y
+}
+
+handle_int() {
+  if [ -n "$ENVNAME" ]; then
+    cleanup "$ENVNAME"
+  fi
+  exit 1
+}
+
+handle_exit() {
+  if [ $? -ne 0 ]; then
+    echo -e "\033[1;31mABORTING.\033[0m"
+    if [ -n "$ENVNAME" ]; then
+      cleanup "$ENVNAME"
+    fi
+  fi
+}
+
+setup_cleanup_handlers() {
+  trap handle_int INT
+  trap handle_exit EXIT
+
+  if is_command_available conda; then
+    __conda_setup="$('conda' 'shell.bash' 'hook' 2>/dev/null)"
+    eval "$__conda_setup"
+    conda deactivate
+  else
+    echo "conda is not available"
+    exit 1
+  fi
+}
+
+# check if a command is present
+is_command_available() {
+  command -v "$1" &>/dev/null
+}