Use types for frames cleanup and refactor

[pbricout]

Here is another batch of changes (still more to come).

There is one important behaviour change in several frames create, it will now throw an error instead of silently ignoring the frame, this is a breaking change but I believe this is better to notify the user rather than silently failing, I started to document this behaviour.

Another change is that the imageBuffer property of the APIC can now be also a filename string, as it shares the code with the COMR frame which was behaving this way.

Finished to remove the generic Data as any which was a TypeScript transition type.

• add more typing in frames
• refactor, clean-up, simplify code
• improve code consistency in style and naming
• add more documentation from id3.org for convenience (I will probably end of adding all of them)
• make the create() and read() function more isomorphic to help reviewing and comparing them
• simplify the main index.ts exports
• changed the way the callback overloads are defined to make it easier to document them, I had to split the definition to be able to document each one of them (I mean to make the documentation more compatible with the tools, VSCode and api-documenter)
• started to make the public documentation strictly follow the tsdoc format, this will work with the future api-documenter
• there is also a misalignment between the FrameBuilder and FrameReader regarding the default usage of the encoding byte, I will probably work on improving this
• removed handling of multiple frame in TXXX frame which I forgot to remove in the previous batch of changes
• language length should be validated everywhere
• biggest changes are in the APIC frame which I tried to simplify with a mitigated success

Scrutinizer rating is stable.

Check the commit message for more details.

Probably best to review with hide white-space changes.

The update of the mocha configuration allows VS code plug-in like Mocha Test Explorer to work, this greatly improves the developer experience when working on tests.

[Zazama]

Another change is that the imageBuffer property of the APIC can now be also a filename string, as it shares the code with the COMR frame which was behaving this way.

Do you think it would make sense to remove this behavior completely instead? We're targeting 0.3, so breaking changes will not affect users who don't manually upgrade.