[mlir][vector] Add more tests for ConvertVectorToLLVM (5/n) (#104784)

This patch aims to disambiguate test names for some of the
Vector-To-LLVM conversion pass.
Covers the following Ops:
  * vector.extractelement
  * vector.extract
  * vector.insertelement
  * vector.insert
  
1. Tests targetting `vector.{insert|extract}` Ops do not have names like
`{insert|extract}_element*` which was confusing against
`vector.{insert|extract}element` ops targetting tests.
2. Tests mention the type of the target/source buffer. e.g.
`@extractelement` => `@extractelement_from_vec_1d`
3. Align LIT ligns consistently with other tests.
4. Tests with a different type for position have a name updated
accordingly. `@extractelement_index` =>`@extractelement_index_position`
5. Tests with a dynamic value for position have a name updated
accordingly. `@extract_element_with_value_1d`
=>`@extract_scalar_dynamic_position_from_vec_1d`
6. Added the scalable flavour of the tests
`insert_scalar_into_vec_2d_dynamic_position` and
`@extract_scalar_from_vec_2d_dynamic_position`

Author: nujaa