[Feature] New bru.scriptpath with path to .bru file in addition to bru.cwd

[gajanak]

I have checked the following:

• I've searched existing issues and found nothing related to my issue.

Describe the feature you want to add

Hi,

I have collections with many Sub Directories for organisation.

It would be nice if there is something like bru.cwd() which returns path to Collection , like
bru.scriptPath() or something... which return path or path+filename to the .bru File.

Background: want to load assets from Directory where the bru file resist.

Perhaps anyone has better idea for a good Name.
Filename or path.

Or does there exist a workaround ? some undocumented Variables ?

Perhaps, This could help #2064 , too.

Thanky you.

Mockups or Images of the feature

// One of:
bru.cwd() // absolute collection  
bru.relativePath() // relative path of current bru to collection
bru.bruFile(), bru.currentFile()  // absolut filename to bru file ?
bru.log("Blub")  // Output send to Timeline Tab for Debugging. (bonus idea)