Represent Vim's buffer name

The format of the buffer name assumed is like

{scheme}://{expr}[;{params}][#{fragment}]

Where

• {scheme} is used to distinguish a buffer kind. It contains only alphabet characters.
• {expr} is used to identify a buffer itself. Unusable characters, semicolons (;), and sharps (#) are replaced with percent-encoded characters.
• {params} (Optional) is used to add meta information to the buffer name like query parameters of URL. Unusable characters and sharps (#) are replaced with percent-encoded characters.
• {fragment} (Optional) is used to add a suffix to the buffer name for file type detection or so on. Unusable characters are replaced with percent-encoded characters.

For example,

denops:///Users/John Titor/test.git
└─┬──┘   └───────────┬────────────┘
  scheme             expr

denops:///Users/John Titor/test.git;foo=foo&bar=bar1&bar=bar2
└─┬──┘   └───────────┬────────────┘ └───────────┬───────────┘
  scheme             expr                       params

denops:///Users/John Titor/test.git#README.md
└─┬──┘   └───────────┬────────────┘ └───┬───┘
  scheme             expr               fragment

denops:///Users/John Titor/test.git;foo=foo&bar=bar1&bar=bar2#README.md
└─┬──┘   └───────────┬────────────┘ └───────────┬───────────┘ └───┬───┘
  scheme             expr                       params            fragment