[Feature]: Allow the container working directory to be specified

[fhke]

Problem

There is presently no way to set the working directory for the launched container. This complicates, and in some cases prevents, the use of relative paths in the container.

Solution

Add a new string type field WorkingDir to the ContainerRequest struct, and use this field to set the WorkingDir field in the Docker Config struct when creating a container.

Benefit

Users of testcontainers can operate on relative paths, and work in an isolated directory, without setting the working directory inside the container.

Alternatives

Depending on the use case users may be able to set the current working directory inside the process, either using the cd shell builtin or native language constructs.

Would you like to help contributing this feature?

Yes

[mdelapenya]

Closed by #1899, thanks!