Pull from Ollama repo functionality

**Is your feature request related to a problem? Please describe.**
Ollama has an easy to use repo, you can pull via short and simple strings.

**Describe the solution you'd like**
Here is a script that can pull from Ollama repo:

```
# To run the relevant tests use
# go test -tags=integration ./server
set -e
set -o pipefail

export OLLAMA_MODELS=test_data/models
REGISTRY_SCHEME=https
REGISTRY=registry.ollama.ai
TEST_MODELS=("library/orca-mini:latest" "library/llava:7b")
ACCEPT_HEADER="Accept: application/vnd.docker.distribution.manifest.v2+json"

for model in ${TEST_MODELS[@]}; do
TEST_MODEL=$(echo ${model} | cut -f1 -d:)
TEST_MODEL_TAG=$(echo ${model} | cut -f2 -d:)
mkdir -p ${OLLAMA_MODELS}/manifests/${REGISTRY}/${TEST_MODEL}/
mkdir -p ${OLLAMA_MODELS}/blobs/

echo "Pulling manifest for ${TEST_MODEL}:${TEST_MODEL_TAG}"
curl -s --header "${ACCEPT_HEADER}" \
-o ${OLLAMA_MODELS}/manifests/${REGISTRY}/${TEST_MODEL}/${TEST_MODEL_TAG} \
${REGISTRY_SCHEME}://${REGISTRY}/v2/${TEST_MODEL}/manifests/${TEST_MODEL_TAG}

CFG_HASH=$(cat ${OLLAMA_MODELS}/manifests/${REGISTRY}/${TEST_MODEL}/${TEST_MODEL_TAG} | jq -r ".config.digest")
echo "Pulling config blob ${CFG_HASH}"
curl -L -C - --header "${ACCEPT_HEADER}" \
-o ${OLLAMA_MODELS}/blobs/${CFG_HASH} \
${REGISTRY_SCHEME}://${REGISTRY}/v2/${TEST_MODEL}/blobs/${CFG_HASH}

cat ${OLLAMA_MODELS}/manifests/${REGISTRY}/${TEST_MODEL}/${TEST_MODEL_TAG}
for LAYER in $(cat ${OLLAMA_MODELS}/manifests/${REGISTRY}/${TEST_MODEL}/${TEST_MODEL_TAG} | jq -r ".layers[].digest"); do
echo "Pulling blob ${LAYER}"
curl -L -C - --header "${ACCEPT_HEADER}" \
-o ${OLLAMA_MODELS}/blobs/${LAYER} \
${REGISTRY_SCHEME}://${REGISTRY}/v2/${TEST_MODEL}/blobs/${LAYER}
done
done
```

Integrate something similar and make it useable

**Describe alternatives you've considered**

**Additional context**