Fix BUR reading scripts

[JGuetschow]

Some BUR reading script currently don't run. As the data have been read it's not urgent to fix, but should be done at some point.

Affected scripts are

• Colombia BUR3 (column already exists when adding aggregated categories)
• Indonesia BUR3 (similar to Colombia)
• Montenegro BUR3 (similar to Colombia)
• Morocco BUR3 (similar to Colombia)
• South Korea 2021 inventory (similar to Colombia)
• South Korea BUR4 (issue with original cat names which are not unique for a given category and have to be removed before conversion to pm2 format)
• Taiwan 2020 inventory (similar to Colombia)

for most cases the errors are in the category aggregation which is done using the process_data_for_country function in newer scripts. Modifying the scripts to also use that function should circumvent the error.