fix: Revert exclusion reason parsing to original logic

[OAbubakr]

Fix exclusion reason parsing and improve apostrophe handling

Problem

After implementing complex regex patterns to handle commas in exclusion reasons, single exclusion reasons like "a, 1" were incorrectly displaying as "(n=a)" instead of "a (n=1)". Additionally, apostrophes were being escaped as \' which displayed incorrectly in the final output.

Root Cause

• Complex regex patterns: The new patterns ",\\s*\\d+\\s*$" and "^.*,\\s*(\\d+)\\s*$" were too strict and failed for simple single exclusion cases
• Apostrophe escaping: Using \' escape sequence caused display issues where apostrophes appeared as backslash-quote combinations

Solution

1. Reverted to original parsing logic

• Reason extraction: Reverted to ",.*$" - removes everything after first comma
• Number extraction: Reverted to ".*," - removes everything before last comma
• This simple approach correctly handles both single and multiple exclusion reasons

2. Improved apostrophe escaping

• Changed apostrophe escaping from \' to HTML entity '
• Preserves apostrophe appearance in final display while preventing DOT syntax errors
• Removed unnecessary backslash escaping that was causing issues

[OAbubakr]