add all scenarios to output of prep_emissions_trajectory()

[cjyetman]

• supersedes add prep_emissions_trajectory() #26 (due to significant changes in 18/convert to package #30)
• depends on a paired PR in https://github.com/RMI-PACTA/pacta-dashboard-svelte being complete (emissions timeline adapts to selected scenario pacta-dashboard-svelte#125)
• works towards feat: Emission intensity plot has a selectable scenario source and scenario pacta-dashboard-svelte#41

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 12 lines in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (d465509) to head (7dffdd2).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
R/prep_emissions_trajectory.R	0.00%	12 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main     #40   +/-   ##
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  Coverage   0.00%   0.00%           
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  Files         21      21           
  Lines        996     997    +1     
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- Misses       996     997    +1     

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[jdhoffa]

You will need to bump the version in DESCRIPTION to Version: 0.0.0.9003 to pass CI

However, apart from that, I have tested this locally in coordination with RMI-PACTA/pacta-dashboard-svelte#121 and proved to myself that this functions as expected:

[cjyetman]

You will need to bump the version in DESCRIPTION to Version: 0.0.0.9003 to pass CI

fine... I was waiting till it was likely to be merged because otherwise it seems likely to end up conflicting with multiple other open PRS... don't really understand how that's supposed to work