SA1520 consistent use of opening and closing braces on if statements

[elachlan]

Relates to #7174
https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1520.md

[sharwell]

💡 Consider updating the .globalconfig to increase the severity of SA1520 to warning. Also note that you can achieve similar results using built-in code analysis rule IDE0011:

# IDE0011: Add braces
csharp_prefer_braces = when_multiline:warning
dotnet_diagnostic.IDE0011.severity = warning

[elachlan]

💡 Consider updating the .globalconfig to increase the severity of SA1520 to warning. Also note that you can achieve similar results using built-in code analysis rule IDE0011:

# IDE0011: Add braces
csharp_prefer_braces = when_multiline:warning
dotnet_diagnostic.IDE0011.severity = warning

If #7192 is merged first, then we can enable the rule/s in the .globalconfig

[Forgind]

Consistency is good, but having unnecessary curly braces always feels wasteful to me. Little bittersweet, but I believe others were less equivocal when we talked about it.