Support more complex String.format rewrites

[niloc132]

https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/Formatter.html#syntax

%[argument_index$][flags][width][.precision]conversion

This will be a multi-part issue, will address them on an as needed basis. The baseline %<conversion> is already supported (just as the default tostring for each type), leaving <argumentIndex>$, <flags>, <width>, and .<precision>, and any extra handling for types.

• argumentIndex support, so arg order is correct
• width for integers - using the example String.format(Locale.US, ".%09d", nanos) from grpc-java - this requires the int/long value be written with a minimum of 9 characters
• flag 0, using the same .%09d - the result will be zero padded
• conversion B/b - null should be false.
• conversion % - write the literal %

...

Items above should be converted into tickets as they are going to be addressed, new items added (make a comment below if you want something added here).

At this time, Locale will continue to not be supported, and will be removed from the expression.