Separate the store directory from the filename in the trace, dag, report, and timeline scopes

[mahesh-panchal]

New feature

It would be nice if the configuration scopes report, trace, dag, and timeline had separate
settings to control the directory they're stored in and separately what to name the file.

report {
    enabled = true
    directory = "${params.outdir}/pipeline_info"
    filename = "report.html"
    overwrite = true
}

Or perhaps have this also somehow linked with the new publishing syntax too since it feels like it should be related in some way.
E.g. rather than a config scope, have a function or something special that's limited in where it can be placed which can be set by the publishing syntax.

workflow {
    ...
 
    publish:
    workflow.dag()      >> 'pipeline_info/'
    workflow.report()   >> 'pipeline_info/'
    workflow.timeline() >> 'pipeline_info/'
    workflow.trace()    >> 'pipeline_info/'
}

Usage scenario

I would like to not change the filename ( and have the timestamp and session_id ), but only update where I want to store
the reports.

Suggest implementation

(Highlight the main building blocks of a possible implementation and/or related components)