Inline trivial implementations

[nazar-pc]

There are many trivial methods in the code that should be inlined (which will help compiler to generate better code).

Especially in cases like this:

parity-scale-codec/src/codec.rs

Lines 1545 to 1547 in 0a0295a

	fn encoded_fixed_size() -> Option<usize> {
	Some(mem::size_of::<$t>())
	}

This is essentially a const method, #[inline(force)] it will reduce the call and corresponding .unwrap() to a constant.

I wanted to submit such a change, but turned out code has a huge number of trivial methods and I wasn't in a mood to do invasive changes.