Various client side lazy evaluation optimizations and bugfix

[pl0xz0rz]

This PR:

• Fixes funCustom when using the template and specifying anonymous functions as variables, before it just crashed by parsing the input with a regex
• Optimizes lazy evaluation when selection formally changes but no actual change happens, at the cost of slightly slowing down evaluation otherwise (factor 4 speedup in usual use case)
• Optimizes swapping out a function used by multiple columns (factor 2 speedup when changing diff function in getDefaultVarsNormAll)
• Removes compute_functions() function as it's not used anywhere
• Fixes warnings in aliTreePlayer.py

[miranov25]

Thank you

Test OK. Real use case was speedup: /lustre/alice/users/miranov/NOTES/alice-tpc-notes2/JIRA/ATO-570/dashboard_IFC.html

Merging