Native API Doc: Fix import and importddi command line examples to double quote url multi arg examples so work.

[kcondon]

It is well known but sometimes forgotten that one needs to double quote curl command lines that have multiple args in the url, specifically that employs & as an arg prefix. Without the quotes it fails due to parsing error. Two recently tested examples involve the :import and :importddi endpoints. Fixing these two would suffice for this issue but a review and correction of all such examples would also be a good choice if time allows.

ex:
curl -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -X POST https://demo.dataverse.org/api/dataverses/root/datasets/:import?pid=doi:ZZ7/MOSEISLEYDB94&release=yes --upload-file dataset.json

curl -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -X POST https://demo.dataverse.org/api/dataverses/root/datasets/:importddi?pid=doi:ZZ7/MOSEISLEYDB94&release=yes --upload-file ddi_dataset.xml

Should be:
curl -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -X POST "https://demo.dataverse.org/api/dataverses/root/datasets/:import?pid=doi:ZZ7/MOSEISLEYDB94&release=yes" --upload-file dataset.json

curl -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -X POST "https://demo.dataverse.org/api/dataverses/root/datasets/:importddi?pid=doi:ZZ7/MOSEISLEYDB94&release=yes" --upload-file ddi_dataset.xml

[landreev]

While we are at it, we should check for any other shell command lines with unqouted ampersands in them that we may have in the guides.
A quick check suggests we have 6 more, all in native-api.rst:

find doc -name '*.rst' | while read rst
do
   if grep -i "curl.* [^\"' ]*/api.*&" "$rst" 
   then
      echo $rst
   fi
done

  curl -H X-Dataverse-key:$API_TOKEN -X POST $SERVER_URL/api/dataverses/$DATAVERSE_ID/datasets/:import?pid=$PERSISTENT_IDENTIFIER&release=yes --upload-file dataset.json
    curl -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -X POST https://demo.dataverse.org/api/dataverses/root/datasets/:import?pid=doi:ZZ7/MOSEISLEYDB94&release=yes --upload-file dataset.json
  curl -H X-Dataverse-key:$API_TOKEN -X POST $SERVER_URL/api/dataverses/$DATAVERSE_ID/datasets/:importddi?pid=$PERSISTENT_IDENTIFIER&release=yes --upload-file ddi_dataset.xml
  curl -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -X POST https://demo.dataverse.org/api/dataverses/root/datasets/:importddi?pid=doi:ZZ7/MOSEISLEYDB94&release=yes --upload-file ddi_dataset.xml
  curl $SERVER_URL/api/datasets/export?exporter=$METADATA_FORMAT&persistentId=PERSISTENT_IDENTIFIER
  curl https://demo.dataverse.org/api/datasets/export?exporter=ddi&persistentId=doi:10.5072/FK2/J8SJZB
  curl -H "X-Dataverse-key: $API_TOKEN" -X PUT $SERVER_URL/api/datasets/:persistentId/editMetadata?persistentId=$PERSISTENT_IDENTIFIER&replace=true --upload-file dataset-update-metadata.json
  curl -H "X-Dataverse-key: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" -X PUT https://demo.dataverse.org/api/datasets/:persistentId/editMetadata/?persistentId=doi:10.5072/FK2/BCCP9Z&replace=true --upload-file dataset-update-metadata.json
doc/sphinx-guides/source/api/native-api.rst