feat: Specify component types in detailed deps page

[414owen]

With the advent of multiple sublibraries per package, it has become less clear what each component is, on the 'detailed dependencies' page.

This changeset replaces the tabulated view of

component name	list of dependencies
- lib 1	- dep 1
	- dep 2
- exe 1	- dep 3

With the more heirarchical:

Libraries

• lib 1
  • dep 1
  • dep 2 ...

Executables

• exe 1
  • dep 3

This change is related to https://github.com/haskell/hackage-server/issues/1218

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Screenshots

Before

After

Obviously, when there are no components of a given type ({Executables, Libraries}), the header itself is not rendered.