Support configuring environment via terminal profiles

[Tyriar]

Suggested in #45444 (comment)

[pszlazak]

Using Terminal profiles (introduced via #45444) I managed to prepare dedicated env for terminals in following way:

• general VS Code config:

    "terminal.integrated.env.linux": {
        "ENVIROMENT": "test"
    },
    "terminal.integrated.profiles.linux": {
        "bash - production": {
            "path": "bash",
            "args": [
                "--rcfile",
                "~/bashrc-prod"
            ],
            "overrideName": true
        },
        "bash - dev": {
            "path": "bash",
            "args": [
                "--rcfile",
                "~/bashrc-dev"
            ],
            "overrideName": true
        },
    },

where terminal.integrated.env.linux sets common variable(s) for all Linux terminals

• content of ~/bashrc-prod:

if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

TYPE=prod

• content of ~/bashrc-dev:

if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

TYPE=dev

In my bash - production I have following variables:

$ echo $ENVIROMENT
test
$ echo $TYPE
prod

In my bash - dev I have following variables:

$ echo $ENVIROMENT
test
$ echo $TYPE
dev

Nevertheless it would be great if something similar to terminal.integrated.env.linux can be used inside definition of profile. E.g.

    "terminal.integrated.env.linux": {
        "ENVIROMENT": "test"
    },
    "terminal.integrated.profiles.linux": {
        "bash - production": {
            "path": "bash",
            "env": [
                "TYPE": "prod"
            ],
            "overrideName": true
        },
        "bash - dev": {
            "path": "bash",
            "env": [
                "TYPE": "dev"
            ],
            "overrideName": true
        },
    },

[Tyriar]

fyi @meganrogge