Provide missing labels and descriptions for buttons

[glowcloud]

Provide labels and descriptions for buttons, e.g.:

• global Authorize button - provide description for authorized/unauthorized state
• operation-level Authorize button - provide indication which operation will be authorized, remove redundant button from the label
• Authorize button - provide indication that the button will open a dialog
• X (close) button in Authorization dialog - provide label
• Remove array item button in parameters - provide label
• Copy to clipboard button - provide label and indication about what will be copied (e.g. cURL)

This task covers issues originally reported in linked sub-issues and:

• [Accessibility] WCAG 2.1 1.3.1, and 4.1.2 && Section 508 502.3.1 && Screen Reader Usability #5248
• Swagger UI is not accessible compliant #7350