Update online event workflow template for more consistent participant amount data and preview-ability

[eileenmcnaughton]

Overview

Update online_event_template to use workflow message

This updates the default online event template to use the variables assigned by
the workflow template

Re the helpful discussion at
#24576

The expectation is that the primaryParticipant gets the values for
all participants whereas the others only get line items,
tax breakdowns, totals that relate to them.

Before

• In ipn mode there are more e-notices and participant data is not loaded for financial stuff for additional participants
• output for additional participants cannot be seen in the Message Admin preview

After

• the new preferred way of loading variables in the WorkflowMessage is used
• the reference to lineItem is replaced by lineItems (slightly less nested & more accurately named) in line with other templates
• we use tokens for the contribution total amount & tax amount
  https://docs.civicrm.org/user/en/latest/email/message-templates/#variables-and-tokens-in-workflow-message-templates
• we no longer refer to the mystical dataArray
• less notices
• I realised the taxBreakdown in the contributionTrait was replacing, not adding to it's array so I fixed that
• new assigned array participants is always avaialble and the template can show all or just the particular participant, depending on whether it is the primeary
• message preveiw works
• does not fatal if secure smarty is enabled

Screenshots from my test - thank you page

Main participant

Second participant

Third

Technical Details

I left several things out of scope - notably the participant profiles & the mystical 'amounts' section

Comments

[civibot]

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