[Enhancement] Support repeating command sequences

[Pante]

Is your feature request related to a problem? Please describe.
At present, adding a repeating sequence of command is more painful than necessary as it is not supported directly by Chimera. Developers wishing to add a repeating sequence need to manually iterate over each sequence and append it to the leaf of the previous sequence.

For example:

var builder = Argument.of("borderSize", IntegerArgumentType.integer(1)).then(Argument.of("borderShrinkTime", LongArgumentType.longArg(1)));
var command = builder.build();
var root = command;

for (var i = 0; i < 10; i++) {
  var child = builder.build();
  command.addChild(child);
  command = child;
}

This is both unwieldy since it needs to be manually re-coded for each repeating sequences and error-prone since iteratively adding sequences requires juggling multiple conditions and variables.

Describe the solution you'd like
We propose adding a repeating(int times) method to Literal and Argument, and their respective builders to facilitate adding repeating sequences.

Additional context
This issue was first raised by MrLn on Discord.