POC: Add template if function and collapse multiple consequent cases

[korzio]

• Check jsperf or other resource that optimization makes sense
• Add template if function
• Replace all validators related if-cases
• Collapse multiple cases, include empty if statements

Possible Syntax

tpl.if('test')
...
tpl.endif() // ?
// => 
'if(test) {}'

Generated function code example

if(a > b) {
  if (c > d) {
    ...
  }
} 
// =>
if(a > b && c > d) {
  ...
}

...
if(a>b){ } 
// =>
// empty