Add residualplot! and lplot! for histogram single fits

[fhagemann]

This lplot! method allows to plot the report of a histogram single fit using LegendSpecFits:

using LegendMakie
using CairoMakie
using LegendSpecFits

result, report = LegendSpecFits.fit_single_trunc_gauss(randn(10000), (low = -4.0, high = 4.0, max = NaN))
lplot(report, xlabel = "x")

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.25%. Comparing base (34e0573) to head (6a40fad).
Report is 5 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main       #2       +/-   ##
===========================================
+ Coverage   70.42%   84.25%   +13.83%     
===========================================
  Files           5        7        +2     
  Lines          71      108       +37     
===========================================
+ Hits           50       91       +41     
+ Misses         21       17        -4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.