LIMS-1422: Reprocessing dialog edits the end value unpredictably

[ndg63276]

JIRA ticket: LIMS-1422

Summary:

The reprocessing dialog tries to help by autofilling the end value, but sometimes that concats a 1 to the start, sometimes adds a 1 to the number resulting in impossible parameters.

As discussed on Slack at https://diamondlightsource.slack.com/archives/CKS8PRR0Q/p1722949258543509

Changes:

• Use Math.round instead of Math.floor or Math.ceil to ensure the image numbers are not affected randomly
• Only autocorrect the start/end image numbers if something has been filled in, rather than putting something in before the user has a chance
• Make the "submitted successfully" message be in green not red.

To test:
First, check the current behaviour.

• Open https://ispyb.diamond.ac.uk/dc/visit/mx23694-118/id/14808375 in a 1920 pixel width Firefox window
• Click the reprocess (cog) icon
• Type a 1 in the Start field, notice how a 1 appears in the End field
• Change the End field to 110, see if it magically changes to 111. If it doesn't, try other numbers, it seems to be a property of the browser and window size. In Chrome, on that data collection, 111 changes to 112.
• Type a number over 3600 in the End field, it should change to 3600
• Click "Integrate" to submit the job, the message window is red

Now load the same page on a dev instance with this PR

• Type a 1 in the Start field, nothing should yet appear in the End field
• Type 110 in the End field, check it doesn't change
• Type a number over 3600 in the End field, it should still change to 3600
• Click "Integrate" to submit the job, the message window should be green