support for xunit-migration

[Meir017]

migrate xunit assertions to fluent-asseertions

the xunit assertion library - https://github.com/xunit/xunit/tree/main/src/xunit.v3.assert and the repo https://github.com/xunit/assert.xunit/

• [ ] #141
• [x] #140
• [ ] #139
• [x] #138
• [x] #137
• [ ] #136
• [x] #135
• [x] #134
• [ ] #133
• [x] #142
• [ ] #143
• [ ] #144
• [x] #145
• [x] #146

[MisinformedDNA]

@Meir017 In the above list, #147 can be removed as it is already covered by #138.

[Meir017]

@MisinformedDNA thanks for pointing this out, I removed that task from the list as it's just the PR item