[feature request] `text=` argument for `read.raxml` function

[Fan-iX]

Prerequisites

• [x] make sure your are using the latest release version
• [x] read the documents
• [x] google your quesion/issue

Describe you issue

Sometimes I have some raxml tree strings in my R session. If I want to read them through read.raxml, I have to create a textConnection, pass it to read.raxml and close it afterward, which takes a lot of unnecessary steps and makes it inconvenient in pipes.

It would be nice if raxml strings could be passed directly to the read.raxml function through a text= arguments, like in data.table::fread(), utils::read.table(), and read.tree()