[Feature] Add official support for different file types.

[Yiannis128]

ESBMC supports the following file types:

• C
• C++
• Java
• And many more.

Currently, ESBMC-AI officially supports only C. The following regions of the program assume C code is being used as input:

• System messages.

Need to add a mechanism that dynamically detects the type of file being worked with. Afterward, load a system message with a correct name for the file. For example, if it is a C file, then the system message should refer to the input as a C file, but if it is a Java file, it should specify Java.

The proposal should add and utilize the following fields in the config file:

"file_types": {
  "java":{
    "singular": "Java source code file",
    "plural": "Java source code"
  },
  "c":{
    "singular": "C source code file",
    "plural": "C source code"
  }
}