Deprecate AbstractMatrix inputs

[heliosdrm]

To deal with #106 and the last comments on #102

With this, using julia --depwarn=yes:

julia> using RecurrenceAnalysis
julia> x=randn(100, 2);
julia> RecurrenceMatrix(x,0.4)
┌ Warning: `RecurrenceMatrix(x::AbstractMatrix, ε; kwargs...)` is deprecated, use `RecurrenceMatrix(Dataset(x), ε; kwargs...)` instead.

But the calculations go as if the matrix had been converted to a Dataset. (By default, in Julia 1.5+ the deprecation warning is hidden).

If this is approved, src/deprecate.jl could be extended later on for RecurrenceMatrix{FAN} etc.

[heliosdrm]

My doubt is: do we want to keep the deprecation warning as it is by default (silent unless you activate the option depwarn=yes, which most people won't do), or is it better to make it more prominent, and always throw the warning to instruct users that Dataset must be used for multi-dimensional data?

[Datseris]

I think the depwarning always has to be thrown. How did you make it "not being thrown by default"? When I use @deprecate or @warn the are always shown when starting Julia the default way.

[heliosdrm]

How did you make it "not being thrown by default"? When I use @deprecate or @warn the are always shown when starting Julia the default way.

I did not make it. It's the default as of Julia 1.5:
https://docs.julialang.org/en/v1/base/base/#Base.@deprecate

[Datseris]

Okay then it is an easy change. Instead of using @deprecate we can instead use @warn inside the function call.

[heliosdrm]

@warn would repeat the message every time matrices are used as inputs, whereas @deprecate would show the message only the first time it happens. Also, according to the answers in Discourse in 1.6 we would be able to force the deprecation message.

Should we make it a regular warning, instead of a deprecation warning, still?

[Datseris]

@warn would repeat the message every time matrices are used as inputs

That's what I always do actually. Don't know if it is good practice or not, but if I know there is some code that will break in the next release, I'd rather press the user to change it as soon as possible instead of passively letting it go after 1 warning.