Bar Chart behaves in unexpected and unintuitive ways when using limit

The Bar chart can be a super powerful aggregation, especially when using as a time based histogram, as shown below:

However there are 2 bugs, one major, one minor:

1. The items shown, after being limited, are seemingly randomly selected and there is no way to sort them. This effectively makes the use of the bar chart not very useful. There is no way to sort the items when applying the limit but there needs to be.
2. The legend at the bottom does not obey the defined limit and shows more items than what the bar chart is showing.

See below for video demonstration of how this looks and behaves:

https://github.com/user-attachments/assets/b40485e3-4d92-42c5-aca5-467f580ea6d6

Please let me know if there are any questions! Always happy to meet to discuss further and provide live demonstrations.

## Expected Behavior

Bar chart with a limit applies allow using a sort to control what items are shown on the bar chart.

## Current Behavior

There is no way to control nor influence what the output of the bar chart looks like.

## Possible Solution

Allow the sort to apply AFTER the aggregation.

## Steps to Reproduce (for bugs)

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## Context

## Your Environment

* Graylog Version: 6.3

## Checklist
[] This issue fix need to be backported.
[] Does this issue have **security** implications?