BUG: Fix password lost when calling `pd.read_sql`

[aresnow1]

What do these changes do?

Use url.render_as_string(hide_password=False) instead of str(url) to keep password during serialization.

Related issue number

Fixes #xxxx

Check code requirements

• [ ] tests added / passed (if needed)
• [ ] Ensure all linting tests pass

[codecov[bot]]

Codecov Report

Merging #545 (5f8894e) into main (00f2f03) will increase coverage by 0.55%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #545      +/-   ##
==========================================
+ Coverage   93.10%   93.66%   +0.55%     
==========================================
  Files        1003     1003              
  Lines       77718    77718              
  Branches    16145    16145              
==========================================
+ Hits        72362    72793     +431     
+ Misses       3732     3294     -438     
- Partials     1624     1631       +7     

Flag	Coverage Δ
unittests	93.56% <100.00%> (+0.55%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...hon/xorbits/_mars/dataframe/datasource/read_sql.py	95.45% <100.00%> (ø)

... and 11 files with indirect coverage changes