Fix workspace file/folder name path cleaning

[AaronPlave]

A regex was being used to remove the workspace path from the filepath in various workspace file/folder create/move modals. This regex failed on workspace names with various characters like parentheses, brackets, etc., that were not being escaped and were therefore being incorporated into the regex string. The resulting filepath for something like "Workspace (A)/foo.txt" would be "Workspace (A)/foo.txt" instead of just "foo.txt", causing a folder with the workspace name to be errantly created during file creation. This PR switches the approach to just remove the first path in the filePath instead of using a regex. Additionally, this PR removes trailing spaces from the end of these filePaths since those also caused creation failures. This should close #1781 which may have also been due to a backend bug that no longer exists - this should resolve all known cases of the issue.

Verification

1. Create a workspace with parentheses in the name like "Workspace (a)"
2. Open the workspace and click the plus button and click on new file
3. Create a file in the root called "foo.txt"
4. Ensure the file is created at the root and not in "Workspace (a)/foo.txt"
5. Repeat 1-4 within a folder in the workspace
6. Repeat 1-5 for folder creation
7. Ensure move workspace file/folder and import workspace file function normally