Enable providing own hadoop for pyspark notebook image

[t92549]

In the hdfs and Accumulo Dockerfiles, users can provide their own builds of Accumulo, ZooKeeper and Hadoop to be used instead of building them inside the image:

gaffer-docker/docker/accumulo/Dockerfile

Lines 50 to 54 in e26dbe7

	# Allow users to provide their own builds of Accumulo, ZooKeeper and Hadoop
	COPY ./files/ .
	# Otherwise, download official distributions
	RUN if [ ! -f "./accumulo-${ACCUMULO_VERSION}-bin.tar.gz" ]; then \
	(wget -nv -O ./accumulo-${ACCUMULO_VERSION}-bin.tar.gz ${ACCUMULO_DOWNLOAD_URL} || wget -nv -O ./accumulo-${ACCUMULO_VERSION}-bin.tar.gz ${ACCUMULO_BACKUP_DOWNLOAD_URL}); \

This can save a lot of time with repeated builds.
This cannot be done, however, for building hadoop inside the pyspark notebook Dockerfile:

gaffer-docker/docker/gaffer-pyspark-notebook/Dockerfile

Lines 34 to 39 in e26dbe7

	ARG HADOOP_VERSION=3.2.2
	ARG HADOOP_DOWNLOAD_URL="https://www.apache.org/dyn/closer.cgi?action=download&filename=hadoop/common/hadoop-${HADOOP_VERSION}/hadoop-${HADOOP_VERSION}.tar.gz"
	ARG HADOOP_BACKUP_DOWNLOAD_URL="https://archive.apache.org/dist/hadoop/common/hadoop-${HADOOP_VERSION}/hadoop-${HADOOP_VERSION}.tar.gz"
	RUN cd /opt && \
	(wget -nv -O ./hadoop-${HADOOP_VERSION}.tar.gz ${HADOOP_DOWNLOAD_URL} || wget -nv -O ./hadoop-${HADOOP_VERSION}.tar.gz ${HADOOP_BACKUP_DOWNLOAD_URL}) && \

It would be great if this was added to that Dockerfile also.