Fix/str safe

[drodarie]

Add safe flag to types.str to prevent default casting. The default attribute type remains however unsafe to keep the default old behavior.

closes #737

[codecov[bot]]

Codecov Report

Merging #746 (ac5a288) into main (5678160) will increase coverage by 0.00%. Report is 6 commits behind head on main. The diff coverage is 92.00%.

@@           Coverage Diff           @@
##             main     #746   +/-   ##
=======================================
  Coverage   74.36%   74.37%           
=======================================
  Files         134      134           
  Lines       15747    15756    +9     
=======================================
+ Hits        11710    11718    +8     
- Misses       4037     4038    +1     

Files Changed	Coverage Δ
bsb/placement/indicator.py	78.78% <ø> (ø)
bsb/placement/strategy.py	84.82% <0.00%> (ø)
bsb/config/types.py	85.59% <90.00%> (+0.04%)	:arrow_up:
bsb/config/_attrs.py	94.96% <100.00%> (+<0.01%)	:arrow_up:
bsb/core.py	70.83% <100.00%> (ø)
bsb/placement/distributor.py	94.19% <100.00%> (ø)
bsb/storage/_files.py	82.22% <100.00%> (ø)
tests/test_configuration.py	99.35% <100.00%> (ø)
tests/test_issues.py	96.66% <100.00%> (ø)