Metadata info: version for update + id/uuid mapping.

[etj]

1) When updating metadata programmatically there is no easy way to get the metadata version number, used by geonetwork to avoid concurrent updates.

2) There is no way to retrieve the internal id of a metadata, given its uuid. This may be a problem if you need to perform a programmatic update, and all you have is the uuid.

The attached patch provides two services:

xml.metadata.info.get

A guest accessible service which takes as query param either "id" or "uuid", and returns both:

e.g. 1

    http://localhost:8080/geonetwork/srv/it/xml.metadata.info.get?id=15

<?xml version="1.0" encoding="UTF-8"?>
<response>
  <id>15</id>
  <uuid>49509107-abc4-4d0a-9b83-2aa27c9f1cb8</uuid>
</response>

e.g. 2

    http://localhost:8080/geonetwork/srv/it/xml.metadata.info.get?uuid=49509107-abc4-4d0a-9b83-2aa27c9f1cb8

<?xml version="1.0" encoding="UTF-8"?>
<response>
  <id>15</id>
  <uuid>49509107-abc4-4d0a-9b83-2aa27c9f1cb8</uuid>
</response>

xml.metadata.info.getForUpdate

An editor-accessible service similar to the above one, but that also increments and return the internal metadata version number:

e.g. 3

   http://localhost:8080/geonetwork/srv/it/xml.metadata.info.getForUpdate?id=15

<?xml version="1.0" encoding="UTF-8"?>
<response>
  <id>15</id>
  <uuid>49509107-abc4-4d0a-9b83-2aa27c9f1cb8</uuid>
  <version>5</version>
</response>

e.g. 4

   http://localhost:8080/geonetwork/srv/it/xml.metadata.info.getForUpdate?uuid=49509107-abc4-4d0a-9b83-2aa27c9f1cb8

<?xml version="1.0" encoding="UTF-8"?>
<response>
  <id>15</id>
  <uuid>49509107-abc4-4d0a-9b83-2aa27c9f1cb8</uuid>
  <version>6</version>
</response>

[fxp]

To get the internal id or uuid, you could use the search service:

• for the UUID: ​http://localhost:8080/geonetwork/srv/eng/q?_uuid=c156fb97-f3ea-4e61-b33f-b48236cb7f30
• for the internal id: ​http://localhost:8080/geonetwork/srv/eng/q?_id=966