[rust] - Introducing new options to install components

[Kaniska244]

Ref: #1273

Description: This PR aims to solve #1273 to introduce new options customComponents and components to install rust components based on user input

Changelog: The following changes are included.

• The installation script is changed to introduce new options customComponents and components (comma separated value for the components to installed ) to install rust components based on user input.
• Change in devcontainer-feature.json by adding the new options customComponents and components to install rust components based on user input.
• Test scripts for different components in different combinations
• The readme file modified with the added information.

Checklist:

• All checks are passed.

[AlvaroRausell]

I am not the biggest fan of having two flags for one action (installing custom components). I would prefer if we did the following:
create a components option, the default being rust-analyzer,rust-src,rustfmt,clippy` (what currently gets installed), but allowing it to be overridden. This will then allow a user to modify this list if required, without changing default behaviour.
So, as a summary:

• Remove customComponents
• Bump minor version.

Once that is done, I will go through the changes again to give a more detailed review

[Kaniska244]

I am not the biggest fan of having two flags for one action (installing custom components). I would prefer if we did the following: create a components option, the default being rust-analyzer,rust-src,rustfmt,clippy` (what currently gets installed), but allowing it to be overridden. This will then allow a user to modify this list if required, without changing default behaviour. So, as a summary:

• Remove customComponents
• Bump minor version.

Once that is done, I will go through the changes again to give a more detailed review

Hello @AlvaroRausell ,

Thank you for the review. I have done changes as per the comments provided. Would you kindly review the PR once again.

[AlvaroRausell]

Good work, just one thing you missed