Large extension of specific_analyses.relax_disp.data(), by adding several helper plotting functions.
This is to prepare for plotting R1rho R2 as function of effective field in rotating frame: w_eff.
R_2 = R1rho / sin^2(theta) - R_1 / tan^2(theta) = (R1rho - R_1 * cos^2(theta) ) / sin^2(theta)
sr #3124(https://gna.org/support/?3124): Grace graphs production for R1rho analysis with R2_eff as function of Omega_eff.
sr #3138(https://gna.org/support/?3138): Interpolating theta through spin-lock offset [Omega], rather than spin-lock field strength [w1].
