Parser: Add dot_notation_tags parser option

[marcoroth]

This pull request adds support for parsing dot-notation component tags like <Dialog.body> and <Dialog.footer> as single HTML elements. A new dot_notation_tags parser option enables this syntax (defaults to false).

When enabled, the parser recognizes <Identifier.identifier> patterns where the first segment starts with an uppercase letter as a single tag name. Subsequent segments can be any valid identifier (uppercase or lowercase). This is similar to how JSX handles compound component patterns.

For example, the following template with dot_notation_tags: true:

<Dialog.wrapper id="demo" title="Confirm">
  <Dialog.body>Are you sure?</Dialog.body>

  <Dialog.footer>
    <Dialog.cancel />
    <Dialog.confirm autofocus />
  </Dialog.footer>
</Dialog.wrapper>

Produces:

@ DocumentNode (location: (1:0)-(9:0))
└── children: (1 item)
    └── @ HTMLElementNode (location: (1:0)-(8:18))
        ├── open_tag:
        │   └── @ HTMLOpenTagNode (location: (1:0)-(1:43))
        │       ├── tag_opening: "<" (location: (1:0)-(1:1))
        │       ├── tag_name: "Dialog.wrapper" (location: (1:1)-(1:15))
        │       ├── tag_closing: ">" (location: (1:42)-(1:43))
        │       ├── children: [...]
        │       └── is_void: false
        │
        ├── tag_name: "Dialog.wrapper" (location: (1:1)-(1:15))
        ├── body: [...]
        ├── close_tag:
        │   └── @ HTMLCloseTagNode (location: (8:0)-(8:18))
        │       ├── tag_name: "Dialog.wrapper" (location: (8:2)-(8:16))
        │       └── ...
        │
        ├── is_void: false
        └── element_source: "HTML"

When dot_notation_tags is true and the first segment starts with a lowercase letter (e.g. <dialog.Button>), a DotNotationCasingError is reported:

@ DotNotationCasingError (location: (1:1)-(1:7))
├── message: "Dot-notation component tags require the first segment to start with an uppercase letter. `dialog` does not start with an uppercase letter."
└── segment: "dialog" (location: (1:1)-(1:7))

This is heavily inspired by Phoenix.Component and JSX.

[pkg-pr-new]

npx https://pkg.pr.new/@herb-tools/formatter@1436

npx https://pkg.pr.new/@herb-tools/language-server@1436

npx https://pkg.pr.new/@herb-tools/linter@1436

commit: ae04c74

[github-actions]

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