Add "multiline-const", "multiline-let" and "multiline-var" STATEMENT_TYPEs to padding-line-between-statements rule

What rule do you want to change? padding-line-between-statements

Does this change cause the rule to produce more or fewer warnings? More

How will the change be implemented? (New option, new default behavior, etc.)? New accepted values for prev and next configuration options

Please provide some example code that this change will affect:

const bouya = { hey: "ho" };
const kasha = {
  tik: "tok",
  onda: "clock"
};

What does the rule currently do for this code? The rule is unable to differentiate single-line and multi-line const, let and var statements.

What will the rule do after it’s changed? The rule will offer the possibility to treat aforementioned cases differently, e.g. enforce blank lines around a multi-line variable declaration but not around a single-line one.

[not-an-aardvark]

To me, it seems confusing to have a type called var that actually means “single-line var statement” (even if we do it after a breaking change). What if we added something like singleline-var and kept var as-is?

[neemzy]

So var would match both single-line and multiline statements, and singleline-var and multiline-var would be added to allow for more specific targetting? That would be fine by me and would indeed avoid introducing a BC break. @platinumazure @not-an-aardvark Do you want me to update the PR accordingly?