PR: Remove quotes from conda-activate.bat params and fix micromamba.exe detection (Installers)

[dalthviz]

Description of Changes

• The installers use a bundled micromamba executable to activate environments but the logic to detect it in conda-activate.bat was not working (the activation was going through the conda option). This caused environments created with a prefix option to not be correctly activated showing the following message:

An error ocurred while starting the kernel
The following argument was not expected: <env path>
Run with ‑‑help for more information.

• When doing a all users install on Windows the default directory for the installation is inside Program Files which has a space in its name. The space was causing problems to run the micromamba command to activate environments

Issue(s) Resolved

Fixes #16562

Affirmation

By submitting this Pull Request or typing my (user)name below,
I affirm the Developer Certificate of Origin
with respect to all commits and content included in this PR,
and understand I am releasing the same under Spyder's MIT (Expat) license.

I certify the above statement is true and correct: dalthviz

[dalthviz]

Note: This could require to also update the micromamba executable version that is bundled with the installer

Edit: Checking with a version of the standalone installer with the latest version of micromamba (1.4.3), the per env environment variables work as expected

[ccordoba12]

Thanks @dalthviz!