Add NumericNode to handle numeric value inputs in AST builder

[panarch]

Now, num AST builder sugar function supports multiple different types including i64, f64, and &str.

e.g.

num("1.23");
num(100_i64);
num(300_i32);
num(1.234);

cc. @ShaddyDC

[coveralls]

Pull Request Test Coverage Report for Build 3530418075

• 76 of 77 (98.7%) changed or added relevant lines in 4 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.006%) to 98.546%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
test-suite/src/ast_builder/basic.rs	6	7	85.71%

Files with Coverage Reduction	New Missed Lines	%
core/src/executor/validate.rs	1	99.32%

Totals
Change from base Build 3521729689:	0.006%
Covered Lines:	37004
Relevant Lines:	37550

---

💛 - Coveralls