Emit CA1305 when a nullable value type does not specify IFormatProvider

[CollinAlpert]

This PR only focuses on nullable value types which represent numbers. If I should extend this for more value types, please let me know.
I also noticed that the fixer was not implemented yet. Are there requirements for a fixer?

Fixes #6586

[codecov]

Codecov Report

Merging #6730 (868f3f5) into main (24890c9) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6730   +/-   ##
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  Coverage   96.32%   96.32%           
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  Files        1389     1389           
  Lines      325104   325128   +24     
  Branches    10721    10722    +1     
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+ Hits       313159   313189   +30     
+ Misses       9234     9228    -6     
  Partials     2711     2711           

[mavasani]

This PR only focuses on nullable value types which represent numbers. If I should extend this for more value types, please let me know.

I think this is good.

[mavasani]

I also noticed that the fixer was not implemented yet. Are there requirements for a fixer?

Yes, indeed - #413 (comment)

[jnm2]

This PR only focuses on nullable value types which represent numbers. If I should extend this for more value types, please let me know.

Does this mean ToString on DateTime? is still not being analyzed? Can we have it automatically apply whenever it would apply on the non-nullable version of the type?

[CollinAlpert]

@jnm2 I've created #7306 to fix this.

[jnm2]

@CollinAlpert You're awesome!

[CollinAlpert]

Thanks :)