Code coverage for design methods

[robertadamsbayer]

Let's first:

• increase coverage, see coverage report accessible from the package website and

• make tests tolerant towards small numeric deviations

• first CRAN release can go without fully refactored methods, otherwise it will take too long

• simulate for RuleDesign (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L514) #798 -> @robertadamsbayer

• simulate for DualDesign (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L698)

• examine generic and method for Design (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L1147)

• examine for DADesign (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L1508)

• simulate for TDSamplesDesign ([https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L1894)]](https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L1894)%5D)

• simulate for TDDesign (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L2260)

• simulate for DualResponsesDesign (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L2610)

• simulate for DualResponsesSamplesDesign (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L3148)

• simulate for DADesign (https://github.com/Roche/crmPack/blob/main/R/Design-methods.R#L4151)

• simulate for DesignGrouped

• simulate for Design with DataOrdinal / new DesignOrdinal