main : update escape_double_quotes() function (#776)

main : update escape_double_quotes() function (#776)

Updated the escape_double_quotes() function such that the function now escapes both double quotes and backslashes in the input string.

Changes Made:

- Renamed the function to escape_quotes_and_backslashes

- Modified the condition in the first loop to increment the value of 'escaped_length' for both double quotes and backslashes.

- Modified the condition in second loop to add a backslash before the current character if it is a double quote or a backslash.

Resolves: #769