Add ParseFloat and replace stod with it

[PragmaTwice]

We add ParseFloat to parse_util.h and replace most of std::stod with this newly added function in this PR.

[torwig]

LGTM

[PragmaTwice]

I notice that gcc implemented floating-point version std::from_chars since 11.1, which is a sad story. It means we cannot use std::from_chars because it comes too late and the gcc version is too new for some users. So I will implement it using strto* in c std library instead.

[PragmaTwice]

I notice that gcc implemented floating-point version std::from_chars since 11.1, which is a sad story. It means we cannot use std::from_chars because it comes too late and the gcc version is too new for some users. So I will implement it using strto* in c std library instead.

done

[git-hulk]

LGTM

[PragmaTwice]

Thanks all. Merging...