Make AnyFrame.renderToString public

[bwjohnson92]

Fixes request in #1129

Two updates regarding the current DataFrame print flow -
Setting AnyFrame.renderToString to public, allowing ability to call it externally.
Updating DataFrame.print to include the rowIndex parameter, as it was the only parameter missing, being passed in to renderToString.

[Jolanrensen]

Thanks! This is very helpful :) It does need some KDocs, but we can add that later.

Since you changed the signature of print(), could you add a @Deprecated version of print() with level HIDDEN with the old signature that simply calls the new one? That way we remain binary compatibility between Beta2 and Beta3+ :)
We usually put a string constant here to keep track of deprecations across cycles. Since the old signature will be unavailable to call in 1.0, you can put it in the "region WARNING in 0.15, ERROR in 1.0".

Also run an apiDump from gradle to update our .api file :).

[bwjohnson92]

Hey! Thanks for the feedback!

A deprecated function signature has been added, with the new message in deprecationMessages, and an apiDump has been run with the changed files pushed! Let me know if you need or want any other changes!

[Jolanrensen]

I ran our CI street, and it looks like there are still some linting errors. This can probably be fixed by running a ktLintFormat from gradle. You can check the build yourself by running build from gradle: https://github.com/Kotlin/dataframe/blob/master/CONTRIBUTING.md#building

[bwjohnson92]

Cheers Jolanrensen - there was indeed some linting errors. ktLintFormat has been run, and the build looks to be working locally. Hopefully that makes the CI happy!