[BUG] salt schedule does not work masterless, offline required

[amalaguti]

Description
Salt scheduler does not work when minion configured in masterless, in order to add a job to schedule the offline: true argument is required in the state. Despite that, once added, in order to list the job with salt-call offline=true is needed but is not possible to run the job on demand, for schedule.run_job offline is not a valid argument.
The job is not found. schedule.show_next_fire_time also does not work.

And also it seems it's not executed on scheduled time either.

PS C:\Windows\system32> salt-call schedule.list offline=true
local:
    schedule:
      schedule_temp_folder_fix:
        args:
        - myapp.myapp_temp_folder
        enabled: true
        function: state.sls
        jid_include: true
        kwargs:
          queue: true
          saltenv: base
        maxrunning: 1
        name: schedule_temp_folder_fix
        return_job: false
        saved: true
        when:
        - Wednesday 11:55am

PS C:\Windows\system32> salt-call schedule.run_job schedule_temp_folder_fix
local:
    ----------
    comment:
        Job schedule_temp_folder_fix does not exist.
    result:
        False

PS C:\Windows\system32> salt-call schedule.run_job schedule_temp_folder_fix offline=true
The following keyword arguments are not valid: offline=True

schedule.show_next_fire_time does not work either:

PS C:\Windows\system32> salt-call schedule.add schedule_temp_folder_fix function='state.sls' args='["tanium.tanium_temp_folder"]' kwargs='{"saltenv": "base", "queue": true}' maxrunning=1 when='Tuesday 6:50am' offline=true
local:
    ----------
    changes:
        ----------
        schedule_temp_folder_fix:
            added
    comment:
        Added job: schedule_temp_folder_fix to schedule.
    result:
        True

PS C:\Windows\system32> salt-call schedule.show_next_fire_time schedule_temp_folder_fix

Passed invalid arguments: argument of type 'NoneType' is not iterable.

Usage:

    Show the next fire time for scheduled job

    .. versionadded:: 2018.3.0

    CLI Example:

    .. code-block:: bash

        salt '*' schedule.show_next_fire_time job_name

Setup
minion in masterless setup with schedule job

file_client: local
use_master_when_local: false
file_roots:
  base:
    - 'G:\\salt\\states'
log_level_logfile: debug
scheduler_before_connect: true

Steps to Reproduce the behavior

• Configure minion in masterless
• Run state to add job or add it with salt-call, without offline=true it fails

PS C:\Windows\system32> salt-call schedule.add schedule_temp_folder_fix function='state.sls' args='["myapp.myapp_temp_folder"]' kwargs='{"saltenv": "base", "queue": true}' maxrunning=1 when='Wednesday 11:55am'
local:
    ----------
    changes:
        ----------
    comment:
        Failed to add job schedule_temp_folder_fix to schedule.
    result:
        False

{%- set schedule_date_time = 'Wednesday 11:55am' %}
{%- set state_file_path = 'myapp.myapp_temp_folder' %}
{%- set job_kwargs = {} %}
{%- do job_kwargs.update({'saltenv': 'base','queue': True}) %}
schedule_temp_folder_fix:
  schedule.present:
    - function: state.sls
    - job_args:
      - {{ state_file_path }}   
    - job_kwargs: {{ job_kwargs }}
    - enabled: true
    - return_job: false
    - offline: true #OFFLINE TRUE
    - when:
      - {{schedule_date_time }}

salt-call schedule.add schedule_temp_folder_fix function='state.sls' args='["myapp.myapp_temp_folder"]' kwargs='{"saltenv": "base", "queue": true}' maxrunning=1 when='Wednesday 11:55am' offline=true

Expected behavior
Given the minion is already set in masterless, I would expect offline to not be required. And more important, the schedule job should run on demand, which it seems not possible due schedule.run_job does not accept offline arg.

Versions Report
3006.7 at leasst