[IMP] owl-vision: syntax scripts, single quotes attributes and slot props highlight and switch below

[BastienFafchamps]

This commit adds the following:

• Syntax builder scripts to make syntaxes easier to read and edit
• Syntax highlight in single quote attributes
• Syntax highlight for slot props
• Basic syntax highlight for xpaths
• Added Switch Below command

It also fixes the following:

• Using Switch Besides or Switch Below does not open a new panel if one was already open
• Fixed missing space in component's snippet indentation