CodePrinter: allow subclasses to easily override _print_NumberSymbol()
CodePrinter: allow subclasses to easily override _print_NumberSymbol()

Instead of assigning `_print_Catalan = _print_NumberSymbol`, just
return `_print_NumberSymbol`.  That way, subclasses can redefine
`_print_NumberSymbol`.

garvitr/sympy,lindsayad/sympy,ga7g08/sympy,Mitchkoens/sympy,wanglongqi/sympy,Vishluck/sympy,jaimahajan1997/sympy,Gadal/sympy,skidzo/sympy,ChristinaZografou/sympy,atreyv/sympy,ahhda/sympy,aktech/sympy,madan96/sympy,sahmed95/sympy,yukoba/sympy,jbbskinny/sympy,cccfran/sympy,garvitr/sympy,chaffra/sympy,sunny94/temp,saurabhjn76/sympy,cswiercz/sympy,Mitchkoens/sympy,Shaswat27/sympy,Titan-C/sympy,vipulroxx/sympy,abhiii5459/sympy,moble/sympy,skirpichev/omg,abloomston/sympy,Designist/sympy,ChristinaZografou/sympy,iamutkarshtiwari/sympy,pandeyadarsh/sympy,shipci/sympy,saurabhjn76/sympy,wyom/sympy,maniteja123/sympy,hargup/sympy,drufat/sympy,Curious72/sympy,aktech/sympy,hargup/sympy,kumarkrishna/sympy,Titan-C/sympy,souravsingh/sympy,AkademieOlympia/sympy,wanglongqi/sympy,yashsharan/sympy,Curious72/sympy,Davidjohnwilson/sympy,yukoba/sympy,mafiya69/sympy,mcdaniel67/sympy,AkademieOlympia/sympy,Mitchkoens/sympy,shikil/sympy,iamutkarshtiwari/sympy,hargup/sympy,jaimahajan1997/sympy,Titan-C/sympy,lindsayad/sympy,Designist/sympy,shikil/sympy,MechCoder/sympy,Arafatk/sympy,ga7g08/sympy,jamesblunt/sympy,AunShiLord/sympy,sampadsaha5/sympy,mafiya69/sympy,beni55/sympy,pandeyadarsh/sympy,cccfran/sympy,sahilshekhawat/sympy,sunny94/temp,asm666/sympy,MechCoder/sympy,Curious72/sympy,VaibhavAgarwalVA/sympy,grevutiu-gabriel/sympy,pandeyadarsh/sympy,asm666/sympy,ahhda/sympy,emon10005/sympy,jamesblunt/sympy,debugger22/sympy,Designist/sympy,vipulroxx/sympy,rahuldan/sympy,maniteja123/sympy,Davidjohnwilson/sympy,wyom/sympy,postvakje/sympy,jamesblunt/sympy,Sumith1896/sympy,chaffra/sympy,abhiii5459/sympy,beni55/sympy,atsao72/sympy,Gadal/sympy,beni55/sympy,grevutiu-gabriel/sympy,mcdaniel67/sympy,skidzo/sympy,Davidjohnwilson/sympy,emon10005/sympy,sahmed95/sympy,VaibhavAgarwalVA/sympy,kumarkrishna/sympy,Vishluck/sympy,oliverlee/sympy,kevalds51/sympy,bukzor/sympy,toolforger/sympy,kaushik94/sympy,AunShiLord/sympy,rahuldan/sympy,cswiercz/sympy,pbrady/sympy,sahilshekhawat/sympy,yashsharan/sympy,MridulS/sympy,jbbskinny/sympy,Gadal/sympy,debugger22/sympy,emon10005/sympy,AkademieOlympia/sympy,Shaswat27/sympy,meghana1995/sympy,souravsingh/sympy,jerli/sympy,garvitr/sympy,rahuldan/sympy,oliverlee/sympy,oliverlee/sympy,sampadsaha5/sympy,mafiya69/sympy,chaffra/sympy,abhiii5459/sympy,postvakje/sympy,shipci/sympy,debugger22/sympy,maniteja123/sympy,moble/sympy,sampadsaha5/sympy,drufat/sympy,farhaanbukhsh/sympy,ChristinaZografou/sympy,pbrady/sympy,drufat/sympy,Vishluck/sympy,meghana1995/sympy,madan96/sympy,kaushik94/sympy,madan96/sympy,pbrady/sympy,VaibhavAgarwalVA/sympy,abloomston/sympy,lindsayad/sympy,kaushik94/sympy,farhaanbukhsh/sympy,Sumith1896/sympy,diofant/diofant,Arafatk/sympy,Arafatk/sympy,shipci/sympy,atreyv/sympy,kaichogami/sympy,aktech/sympy,liangjiaxing/sympy,cccfran/sympy,sahilshekhawat/sympy,liangjiaxing/sympy,ga7g08/sympy,souravsingh/sympy,iamutkarshtiwari/sympy,jbbskinny/sympy,postvakje/sympy,wanglongqi/sympy,kaichogami/sympy,shikil/sympy,asm666/sympy,yukoba/sympy,MechCoder/sympy,sahmed95/sympy,farhaanbukhsh/sympy,Sumith1896/sympy,meghana1995/sympy,jerli/sympy,vipulroxx/sympy,atreyv/sympy,yashsharan/sympy,AunShiLord/sympy,skidzo/sympy,atsao72/sympy,saurabhjn76/sympy,jaimahajan1997/sympy,cswiercz/sympy,kevalds51/sympy,bukzor/sympy,MridulS/sympy,wyom/sympy,Shaswat27/sympy,mcdaniel67/sympy,MridulS/sympy,liangjiaxing/sympy,grevutiu-gabriel/sympy,jerli/sympy,bukzor/sympy,abloomston/sympy,atsao72/sympy,kumarkrishna/sympy,kaichogami/sympy,kevalds51/sympy,sunny94/temp,toolforger/sympy,toolforger/sympy,moble/sympy,ahhda/sympy