fix(ui): preserve block content formatting when parsing chat messages

Remove trimming of block content when parsing chat messages to ensure
that formatting, such as leading and trailing whitespace, is preserved.
This prevents unintended loss of formatting in code or text blocks
within chat sections.

Author: deathbeam

lua/CopilotChat/ui/chat.lua

@@ -734,7 +734,7 @@ function Chat:parse()
     message.content = vim.trim(table.concat(message.content, '\n'))
     if message.section then
       for _, block in ipairs(message.section.blocks) do
-        block.content = vim.trim(table.concat(block.content, '\n'))
+        block.content = table.concat(block.content, '\n')
       end
     end