Bit length vs Byte length bug fix in string_length

[zwimer]

Bit length vs Byte length bug fix in string_length

[github-actions]

Test Results

     96 files  +     86       96 suites  +86   1h 32m 17s ⏱️ + 1h 31m 43s
1 467 tests +1 161  1 376 ✔️ +1 130  90 💤 +30  0 ❌ ±0  1 🔥 +1 
1 473 runs  +1 167  1 382 ✔️ +1 136  90 💤 +30  0 ❌ ±0  1 🔥 +1 

For more details on these errors, see this check.

Results for commit 6b81e46. ± Comparison against base commit 4b21cf9.

♻️ This comment has been updated with latest results.

[zwimer]

@rhelmot In case it is unintended, making an IntToStr with args (<BV32 0xc>,) and kwargs {'length': 80000, 'uninitialized': None} leads to the eager backend logic in __new__ invoking leading to creating a different AST with a different length.

I.e. The output length is 16 bits long instead of 80000 bits.

I updated the PR to keep .length and .bit_length sync'd given this, but it might be worth a look if that isn't expected.