Fix imports for commonly-named components

[nmanu1]

This PR fixes imports for commonly-named components like Container and Text by manually writing their imports to the file before calling ts-morphs fixMissingImports function. Previously, this function would often add an incorrect import in the case of Container and not add any import in the case of Text, which is also a built-in interface in React.

J=SLAP-2587
TEST=auto, manual

Added postcss to the test site and saw that without these changes, Container was imported from postcss (which also has a named export called Container), and that with these changes, Container is correctly imported from src/components. Also saw that the behavior for Text was fixed (i.e. an import was actually added for a Text component rather than it trying to use the React type).

[tmeyer2115]

This PR fixes imports for commonly-named components like Container and Text by manually writing their imports to the file before calling ts-morphs fixMissingImports function. Previously, this function would often add an incorrect import in the case of Container and not add any import in the case of Text, which is also a built-in interface in React.

J=SLAP-2587 TEST=auto, manual

I wasn't able to replicate the incorrect Container import in the test-site because we don't have any packages like postcss that have another named export called Container. But, I was able to see the behavior for Text fixed (i.e. an import was actually added for a Text component rather than it trying to use the React type).

Since the impetus of the item was the incorrect Container import, could you add postcss to the test site? I'd like to verify that we've fixed the bug for Container. We don't need to check in those changes to the test site, I'd just like us to verify it manually.

[nmanu1]

Since the impetus of the item was the incorrect Container import, could you add postcss to the test site? I'd like to verify that we've fixed the bug for Container. We don't need to check in those changes to the test site, I'd just like us to verify it manually.

Added postcss to the test site and confirmed that without the changes in this PR, Container was imported from postcss and with the changes, Container is correctly imported from src/components!