Problem description: Imagine that You're using zabbix 5.2 and have a host with an aggregated item that uses the macro + time suffix combination as the "Last of" parameter, for example:

 grpavg[\{$M},trap1,avg,\{$M3}s] 

.
After upgrading such configuration to the latest master such function is converted into the formula in following format, without quoting the macro + time suffix combination:

 avg(avg_foreach(/*/trap1?[group="\{$M}"],\{$M3}s)) 

As result, if the user exports such configuration from master, he will not be able to import it anymore without inserting the quotes manually.

Steps to reproduce:

1. Open zabbix 5.2
2. Import the following configuration: macro_with_suffix_aggregate.yaml
3. upgrade database to the latest master (currently 5.4.0rc1)
4. Open configuration of the "a9" item under hot "aggregate" and check "Formula" field
   Result 1: in the formula the macro + time suffix combination is not quoted.
5. Export configuration of this host and attempt to import it.
   Result 2: it is not possible to import the host due to missing quotes:

    Invalid parameter "/1/params": incorrect expression starting from "avg(avg_foreach(/*/trap1?[group="\{$M}"],\{$M3}s))". 

Expected: the macro + time suffix combination should be quoted during conversion when upgrading the database, for example:

 avg(avg_foreach(/*/trap1?[group="\{$M}"],"\{$M3}s")) 

See screenshot....
See attached patch file...