Include missing HLT2 lines for strange decays

Following !1527 (merged), this MR aims at implementing remaining lines described in https://arxiv.org/abs/1808.03477 for decays that are of interest from the theoretical point of view and that can be studied at LHCb. Here we implement (including charge-conjugate processes):

Remaining lines for kaon decays

• K_S^0\to\pi^+\ell^-\bar{\nu}_\ell
• K_S^0\to\ell^+(\pi^+)\ell^-(\pi^-)\ell^{(\prime)+}\ell^{(\prime)-}
• K_S^0\to (X^0)\mu^+\mu^-
• K^+\to\pi^+\ell^-\ell^+

Lines on Hyperon decays

• \Lambda\to p\ell^-\bar{\nu}_\ell
• \Sigma^+\to p\ell^{(\prime)+}\ell^-
• \Xi^0\to p\pi^-
• \Xi^-\to p\pi^-\pi^-
• \Xi^-\to \Lambda \ell^- (\bar{\nu}_\ell~)
• \Omega^-\to\Lambda\pi^-

Together with different control/normalization modes.

Supersedes !1256 (closed)