Introduce an option to check macro presence in LLD filters

Currently, there is a limitation of LLD rule filtering that doesn't allow to process objects with LLD macro missing.

For example, according to the documentation (SNMP discovery):

If an entity does not have the specified OID, then the corresponding macro will be omitted for this entity.

At this point, having a filter like "{#MACRO} doesn't match VALUE" will fail to execute with the following error:

Cannot accurately apply filter: no value received for macro "{#MACRO}"

At this point, it seems that having something like "{#MACRO} exist" / "{#MACRO} doesn't exist" as an option for the LLD rule filter is a solution.