This PR fixes #114473

The string ${abc:test} ${abc} would result in commandValueMapping having:

{
    "abc": "${abc}",
    "abc:test": "${abc:test}"
}

where resolveFromMap would get "abc" for both variables, resulting in ${abc:test} being replaced with ${abc}, disregarding the splitting of abc:test into ['abc', 'test'] that happened beforehand.

This PR makes the call to resolveFromMap recreate the original variable ("abc:test") to pass to it. Running the example code in the mentioned issue with this fix produces the following output:

> Executing task: ABC <

Original: echo '${workspaceFolderBasename}' '${def:arg}' '${abc:test}' '${abc}' '${abc:def}' '${xyz:123}' '${xyz:456}'
Resolved: echo 'Empty workspace' '${def:arg}' '${abc:test}' '${abc}' '${abc:def}' '${xyz:123}' '${xyz:456}'

Terminal will be reused by tasks, press any key to close it.

The ${abc:test} remains ${abc:test}, unlike before where it would've been "resolved" to ${abc} instead.