Make analyzing suggester more flexible [LUCENE-4491]

Today we have a analyzing suggester that is bound to a single key. Yet, if you want to have a totally different surface form compared to the key used to find the suggestion you either have to copy the code or play some super ugly analyzer tricks. For example I want to suggest "Barbar Streisand" if somebody types "strei" in that case the surface form is totally different from the analyzed form.

Even one step further I want to embed some meta-data in the suggested key like a user id or some type my surface form could look like "Barbar Streisand|15". Ideally I want to encode this as binary and that might not be a valid UTF-8 byte sequence.

I'm actually doing this in production and my only option was to copy the analyzing suggester and some of it's related classes.

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Migrated from [LUCENE-4491](https://issues.apache.org/jira/browse/LUCENE-4491) by Simon Willnauer (@s1monw), 1 vote, updated May 09 2016
Attachments: [LUCENE-4491.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-4491/LUCENE-4491.patch) (versions: 2)