Add php and lib-base as special libraries to add dependencies to the root node

[crazywhalecc]

What does this PR do?

Add php and lib-base as special libraries to add dependencies to the root node. Preparation for #611 .

The main changes are to use php as a special root library and add lib-base as the root library of the original library.

At the same time, lib.json becomes 4 types: root, target, package, lib, representing:

• root: root node, only php and lib-base.
• target: virtual library, which may be depended by other libraries but not an independent library, such as micro SAPI.
• package: build target is binary dependency, such as pkg-config, which can be depended by the root node.
• lib: ordinary dependency library.

cc @DubbleClick

Checklist before merging

If your PR involves the changes mentioned below and completed the action, please tick the corresponding option.
If a modification is not involved, please skip it directly.

• If it's an extension or dependency update, make sure adding related extensions in src/global/test-extensions.php.
• If you changed the behavior of static-php-cli, update docs in ./docs/.
• If you updated config/xxx.json content, run bin/spc dev:sort-config xxx.