Add Table.distinct function to In-Memory table

[radeusgd]

Pull Request Description

Implements https://www.pivotaltracker.com/story/show/182307143

Important Notes

• Modified standard library Java helpers dependencies so that std-table module depends on std-base, as a provided dependency. This is allowed, because std-table is used by the Standard.Table Enso module which depends on Standard.Base which ensures that the std-base is loaded onto the classpath, thus whenever std-table is loaded by Standard.Table, so is std-base. Thus we can rely on classes from std-base and its dependencies being provided on the classpath. Thanks to that we can use utilities like Text_Utils also in std-table, avoiding code duplication. Additional advantage of that is that we don't need to specify ICU4J as a separate dependency for std-table, since it is 'taken' from std-base already - so we avoid including it in our build packages twice.

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the
  Scala,
  Java,
  and
  Rust
  style guides.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed: Enso GUI was tested when built using BOTH
    ./run ide build and ./run ide watch.