CONTRIB-9440: fix for fixed number of parameters

[jfederico]

This solves the bug for the fixed number of parameters, but we may want to refactor the way the data is handled so instead of 3 disconnected arrays like this

{
"flexurl_eventtype":["2","1","2","2"],
"flexurl_paramname":["custom_name","another","global_param_new","new_more"],
"flexurl_paramvalue":["user.alternatename","activityinfo.name","courseinfo.idnumber","activityinfo.id"]
}

we have a distinct objcet per row like this

[
[{"flexurl_eventtype":2},{"flexurl_paramname":"custom_name"},{"flexurl_paramvalue":"user.alternatename"}],
[{"flexurl_eventtype":1},{"flexurl_paramname":"another"},{"flexurl_paramvalue":"activityinfo.name"}],
[{"flexurl_eventtype":2},{"flexurl_paramname":"global_param_new"},{"flexurl_paramvalue":"courseinfo.idnumber"}],
[{"flexurl_eventtype":2},{"flexurl_paramname":"new_more"},{"flexurl_paramvalue":"activityinfo.id"}],
]

of course this would lead to a bigger change as the logic for rendering the data would need to change