✨ Simplify constructors for `Zero`

[LVMVRQUXL]

📝 Description

For aligning with our design goals on less is more, we want to provide only constructors for creating an instance of the Zero type in a natural way. These constructors should be accessible from all Kotlin platforms and Java.

Here's the Application Programming Interface (API) goal that we want to achieve with this issue:

class Zero {
    constructor() // Already introduced in v4.5.1.
    constructor(number: Any)
}

These constructors should replace all factory functions introduced previously for the Zero type.

Also, the Zero.Companion.PATTERN property being used only by the constructor(Any) function of the Zero type, we want to remove it from the public experimental API and merge its documentation into this constructor's documentation.

✅ Checklist

• [x] ✨ Add the constructor(Any) function with tests, documentation and samples.
• [x] 📝 Update the documentation of the Zero type for removing factory functions other than constructors.
• [x] 🔥 Remove all other factory functions for the Zero type and unused internals.
• [x] 📝 Update the documentation of the constructor(Any) function for removing usages of the Zero.Companion.PATTERN property.
• [x] ♻️ Refactor the constructor(Any) function for removing usages of the Zero.Companion.PATTERN property.
• [x] 🔥 Remove the Zero.Companion.PATTERN property.
• [x] 🔥 Remove the Zero.Companion type.
• [x] ♻️ Refactor the constructor(Any) function by introducing an internal InvalidZeroRepresentation type.
• [x] 📝 Update the unreleased changelog for this issue.
• [ ] 💬 Resolve all comments of this issue.

[LVMVRQUXL]

After resolving this issue, we will be able to introduce the ZeroAsStringSerializer type in the types-kotlinx-serialization subproject for serializing the Zero type as String. This could be useful for communicating an already formatted zero like 0.00.

[LVMVRQUXL]

Using RegExr might be a solution for storing and documenting the regular expression used by the constructor(Any) function.

[LVMVRQUXL]

Superseded by #681.