Add alternative solutions to output from ascat.runAscat()

[MartinezRuiz-Carlos]

Added code written by Prof. Nicolai Juul Birkbak back in 2015 to output all alternative solutions when running ascat.runAscat().

• The alternative solutions are stored as a data.frame in the output object under alternative_solutions
• The alternative_solutions data.frame outputs psi_ploidy, rho_aberrant_cell_fraction and goodness_of_fit
• The commit should deal with the issue raised here
• The changes have been tested successfully on 6 WES tumour samples

Session info of the tests:

R version 4.5.2 (2025-10-31)
Platform: x86_64-pc-linux-gnu
Running under: Debian GNU/Linux forky/sid

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3 
LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/libopenblasp-r0.3.30.so;  LAPACK version 3.12.0

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

time zone: Etc/UTC
tzcode source: system (glibc)

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] ASCAT_3.2.0

loaded via a namespace (and not attached):
 [1] RColorBrewer_1.1-3   codetools_0.2-20     doParallel_1.0.17   
 [4] splines_4.5.2        iterators_1.0.14     parallel_4.5.2      
 [7] BiocGenerics_0.56.0  generics_0.1.4       stats4_4.5.2        
[10] Seqinfo_1.0.0        foreach_1.5.2        GenomicRanges_1.62.0
[13] IRanges_2.44.0       data.table_1.17.8    compiler_4.5.2      
[16] tools_4.5.2          S4Vectors_0.48.0