Enable multi-level decodings to actually work (Caesar) in multi-level paths

[bee-san]

Previously when we had something like:

Caesar -> Base64

Ares (and Ciphey) would take the first decoding of Caesar (Rot1(X)) and pass that to Base64. This PR makes it so all 25 shifts of Caesar (and other similar ciphers) are passed to the decoders.

This works by....

Every Text struct contains a field:

text: Vec<String>,

Which contains every decoding (even if it's just 1 decoding).

After each iteration of BFS we loop over all of our vectors we have collected and flatten them from a Vec<Vec<Text>> to a Vec<Text> where text: Vec<String> has a single element (meaning we can index into the 0th element [0] and get the result).

        let mut new_strings_to_be_added = Vec::new();
        for textStruct in new_strings{
            for decoded_text in textStruct.text{
                new_strings_to_be_added.push(
                    Text {
                        text: vec![decoded_text],
                        // quick hack
                        path: textStruct.path.clone(),
                    }
                )
            }

This introduces some issues:

1. It is not efficient to have a O(n^2) loop after our big main loop
2. We are using .clone() here which is slow
3. It is not efficient to make a new vector with just 1 element
4. It does not support nice paths. If it was Caesar, it won't say "Caesar with shift of 13" for example

This is a hack to get us to support this feature.

In the future we might want to look at:

Editing this bit of code so it supports Vectors of Vectors:
https://github.com/bee-san/Ares/blob/1bcc994052db17e7db948055d012810353c76f4d/src/searchers/bfs.rs#LL32-L33C69

Or adding another loop below this code so it turns into a O(n^2) nested loop:

Ares/src/searchers/bfs.rs

Line 26 in 1bcc994

while !current_strings.is_empty() {