Add a 2D plot script for raw material scan

[Chao1009]

Briefly, what does this PR introduce?

A script to generate 2D plots

What kind of change does this PR introduce?

• Bug fix (issue #__)
• New feature (issue #__)
• Documentation update
• Other: __

Please check if this PR fulfills the following:

• Tests for the changes have been added
• Documentation has been added / updated
• Changes have been communicated to collaborators

Does this PR introduce breaking changes? What changes might users need to make to their code?

No

Does this PR change default behavior?

No

[Chao1009]

Plan to move all the related scripts to benchmarks

[Chao1009]

To use it (assuming under dir epic):

mkdir scan_test
cd scan_test
../bin/g4MaterialScan_to_csv -c ${DETECTOR_PATH}/epic_craterlake.xml --raw-output --phi=0. --eta=-4:4:0.01
../bin/g4MaterialScan_raw_plot_2d --phi=0. --eta=-4:4:0.01

[Chao1009]

Linear scale
../bin/g4MaterialScan_raw_plot_2d --eta=-4:4:0.01 --plot-scale=linear

Log scale
../bin/g4MaterialScan_raw_plot_2d --eta=-4:4:0.01

[Chao1009]

A zoomed-in plot for the tracking region

Linear scale
../bin/g4MaterialScan_raw_plot_2d --eta=-4:4:0.01 --z-min=-250 --z-max=250 --r-max=100 --x0-min=0 --x0-max=0.2 --lambda-min=0 --lambda-max=0.2 --plot-scale linear

Log scale
../bin/g4MaterialScan_raw_plot_2d --eta=-4:4:0.01 --z-min=-250 --z-max=250 --r-max=100

[Chao1009]

The scripts related to material scans will be moved to benchmarks in the following PR.