Find By Example With Array

[PauloFerreira25]

Hello gentlemen.
This PR contains an improvement allowing to search for content that is within an array in the document.
Ex: search for the document that has a list of sub documents and in that list has an attribute with a value.
object A = {list: [{attribute: value}]}

I believe that there must be a better way to do the entire ArangoExampleConverter class, but I limited myself to just implementing the missing function. Any day, we can talk about this refactory.

Thanks for listening. Keep up the good work.

[rashtao]

Thanks for the contribution!

I think the PR is OK, nevertheless some parts of the API could have been implemented in different ways. Eg. array elements matchers are always chained with OR, even in case of ExampleMatcher.matchingAll().

For such cases, it would be beneficial discussing about the specs and planning the related work in advance, eg. in the Spring Data ArangoDB Slack channel (https://arangodb-community.slack.com/archives/CE0TYRHK5).
Also feel free to send me a private message if you prefer.