make sure Filter predicates are always serializable

[tyrasd]

Description

Makes sure users don't have to manually make supplied lambdas serializable when using Filter.by*.

Currently (0.6.*) users need to do this workaround when executing a query with a filter on ignite:

….filter(Filter.byOSMEntity((SerializablePredicate<OSMEntity>) e -> e.getVersion() == 42)

After this fix, this should be sufficient:

….filter(Filter.byOSMEntity(e -> e.getVersion() == 42)

This PR creates a local copy of the existing SerializablePredicate class as a an inner interface of the Filter class in order to avoid a circular dependency between the oshdb-filter and oshdb-api modules.

Checklist

• My code follows the code-style rules, and I have checked on the static analyses and benchmark (if applicable) results
• I have commented my code
• I have written javadoc (required for public methods)
• I have added sufficient unit tests
• I have made corresponding changes to the documentation
• I have updated the CHANGELOG.md
• I have adjusted the examples or created an issue in the corresponding repository
• I have adjusted the benchmark or created an issue in the corresponding repository

[rtroilo]

looks good