Describe the feature:

Part of #217967

TS command will support some functions which will be available only when the users are using TS as the source command. Some of them are:

• RATE
• max_over_time
• min_over_time
• count_over_time
• avg_over_time
• last_over_time
• first_over_time
• percentile_over_time

The ES team will add them to the functions definitions with a flag so we can now that these are TS functions. We need to change our script and our functions logic to suggest these functions correctly