global: convert brk_vecs to its own crates and repo (seqdb/vecdb) + changes

TODO.md

@@ -60,11 +60,6 @@
       - add extensions support (.json .csv …)
       - if format instead of extension then don't download file
     - add support for https (rustls)
-    - lru cache
-  - _vec_
-    - add native lock file support (once it's available in stable rust)
-    - improve compressed mode (slow reads)
-    - add ema support
 - __docs__
   - _README_
     - add a comparison table with alternatives