Add update mode to Table.Running

[AdRiley]

Pull Request Description

Table.Running needed an update mode to allow overwriting existing columns

Important Notes

Would appreciate second opinions on

group_builder.specify "Not setting the name updates the first column if update_mode update"

That is the one behaviour I am uncertain about

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.