[5.7] Add ability to update any section of package.json

[nulpatrol]

In continuation of the previous PRs (#24189, #25457 ) I suggest one more.
I noticed that developers who need to update, for example, a section of scripts, often completely overwrite the existing package.json file.
Let's give ability to pass name of section as parameter of static::updatePackages.

static::updatePackages('scripts');

For back compatibility, we also support boolean as parameter.

Maybe there are best variants for doing this, but I think, that this variant is the least breaking.

[taylorotwell]

Passing a bool to this method feels like a really hacky way to try to keep it backward compatible. I would rather have it always be a string.

[nulpatrol]

@taylorotwell Can I submit PR to 5.8 with string param?

[X-Coder264]

@nulpatrol Please send it to 5.8, yes.